Object 1 WebAssign Welcome, jeremy.guillory@grandcanyon (log out) Friday, November 18 2016 03:11 AM MST Home My Assignments Grades Communication Calendar My eBooks My Ebooks Introduction to the Practice of Statistics - 8e Moore, McCabe, and Craig Introduction to the Practice of Statistics - 8e Moore, McCabe, and Craig You have not purchased access to this eBook. Purchase eBook Access Notifications Help My Options MAT 274, section BM 10102016, Fall 2016 My Assignments Topic Six Homework (Homework) Jeremy Guillory MAT 274, section BM 10102016, Fall 2016 Instructor: Bhavisha Modi Current Score : - / 20 Due : Sunday, November 20 2016 11:58 PM MST Extension Requests Print Assignment Question Points 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 -/0.64 -/0.64 -/0.64 -/0.64 -/0.64 -/0.64 -/0.64 -/0.64 -/0.64 -/0.64 -/0.64 -/0.64 -/0.64 -/0.64 -/0.64 -/ Total -/20 (0.0%) Description Chapter 12 and 13 Assignment Submission For this assignment, you submit answers by question parts. The number of submissions remaining for each question part only changes if you submit or change the answer. Assignment Scoring Your last submission is used for your score. 1. -/0.64 points MIntroStat8 12.E.013. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Question Part Send Points Submissions Used 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 -/0.03 -/0.03 -/0.03 -/0.03 -/0.03 -/0.03 -/0.03 -/0.03 -/0.03 -/0.03 -/0.03 -/0.03 -/0.03 -/0.03 -/0.03 -/ 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/ Total -/0.64 For each of the following situations, identify the response variable and the populations to be compared, and give I, the ni, and N. (a) A poultry farmer is interested in reducing the cholesterol level in his marketable eggs. He wants to compare two different cholesterol-lowering drugs added to the hen's standard diet as well as an allvegetarian diet. He assigns 25 of his hens to each of the three treatments. Response variable: egg cholesterol level caloric intake diet cholesterol level number of marketable eggs laid number of hens Populations: (Select all that apply.) all eggs laid on a farm all hens on a farm hens on an all-vegetarian diet hens on a standard diet and receiving one of two cholesterol-lowering drugs eggs with different cholesterol levels I = Enter an exact number. 3 n1 = Enter an exact number. 4 n2 = Enter an exact number. 5 n3 = Enter an exact number. 6 N = Enter an exact number. 7 (b) A researcher is interested in students' opinions regarding an additional annual fee to support nonincome-producing varsity sports. Students were asked to rate their acceptance of this fee on a five-point scale. She received 90 responses, of which 31 were from students who attend varsity football or basketball games only, 18 were from students who also attend other varsity competitions, and 41 who did not attend any varsity games. Response variable: acceptance rating on a five-point scale varsity sport played games amount of annual fee paid number of games attended number of students who attend varsity Populations: (Select all that apply.) students who attend varsity football or basketball games students who pay an annual fee students who attend other varsity competitions students who do not attend any varsity games students who play sports I = Enter an exact number. 10 n1 = Enter an exact number. 11 n2 = Enter an exact number. 12 n3 = Enter an exact number. 13 N = Enter an exact number. 14 (c) A professor wants to evaluate the effectiveness of his teaching assistants. In one class period, the 39 students were randomly divided into three equal-sized groups, and each group was taught power calculations from one of the assistants. At the beginning of the next class, each student took a quiz on power calculations, and these scores were compared. Response variable: rating of the professor on a five-point scale quiz score number of questions on the quiz course grade rating of the assistant on a five-point scale Populations: (Select all that apply.) students passing the course students in the three TA groups teaching assistants all students at the school I = Enter an exact number. 17 students who like their TA the three n1 = Enter an exact number. 18 n2 = Enter an exact number. 19 n3 = Enter an exact number. 20 N = Enter an exact number. 21 Submit Answer Save Progress Submit Assignment Your work in question(s) will also be submitted or saved. Save Assignment Progress Practice Another Version Viewing Saved Work Revert to Last Response 2. -/0.64 points MIntroStat8 12.E.015. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Question Part Send Points Submissions Used 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 -/0.03 -/0.03 -/0.03 -/0.03 -/0.03 -/0.03 -/0.03 -/0.03 -/0.03 -/0.03 -/0.03 -/0.03 -/0.03 -/0.03 -/0.03 -/ 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/ Total -/0.64 For each of the following situations, give the degrees of freedom for the group (DFG), for error (DFE), and for the total (DFT). State the null and alternative hypotheses, H0 and Ha, and give the numerator and denominator degrees of freedom for the F statistic. (a) A poultry farmer is interested in reducing the cholesterol level in his marketable eggs. He wants to compare two different cholesterol-lowering drugs added to the hen's standard diet as well as an allvegetarian diet. He assigns 15 of his hens to each of the three treatments. Enter an exact number. DFG = 1 DFE = Enter an exact number. 2 DFT = Enter an exact number. 3 H0: The all-vegetarian diet group has a lower mean cholesterol level. All groups have different mean cholesterol levels. At least one group has a different mean cholesterol level. All groups have the same mean cholesterol level. The all-vegetarian diet group has a higher mean cholesterol level. Ha: All groups have the same mean cholesterol level. The all-vegetarian diet group has a higher mean cholesterol level. At least one group has a different mean cholesterol level. All groups have different mean cholesterol levels. The all-vegetarian diet group has a lower mean cholesterol level. numerator df Enter an exact number. 6 denominator df Enter an exact number. 7 (b) A researcher is interested in students' opinions regarding an additional annual fee to support nonincome-producing varsity sports. Students were asked to rate their acceptance of this fee on a seven-point scale. She received 98 responses, of which 31 were from students who attend varsity football or basketball games only, 16 were from students who also attend other varsity competitions, and 51 who did not attend any varsity games. Enter an exact number. DFG = 8 DFE = Enter an exact number. 9 DFT = Enter an exact number. 10 H0: The group of students who do not attend games has a higher mean rating. All groups have different mean ratings. The group of students who do not attend games has a lower mean rating. At least one group has a different mean rating. All groups have the same mean rating. Ha: The group of students who do not attend games has a lower mean rating. All groups have different mean ratings. At least one group has a different mean rating. The group of students who do not attend games has a higher mean rating. All groups have the same mean rating. numerator df Enter an exact number. 13 denominator df Enter an exact number. 14 (c) A professor wants to evaluate the effectiveness of his teaching assistants. In one class period, the 45 students were randomly divided into three equal-sized groups, and each group was taught power calculations from one of the assistants. At the beginning of the next class, each student took a quiz on power calculations, and these scores were compared. DFG = Enter an exact number. 15 DFE = Enter an exact number. 16 DFT = Enter an exact number. 17 H0: The group taught by the oldest TA has a lower mean quiz score. All groups have different mean quiz scores. The group taught by the oldest TA has a higher mean quiz score. All groups have the same mean quiz score. At least one group has a different mean quiz score. Ha: At least one group has a different mean quiz score. The group taught by the oldest TA has a higher mean quiz score. The group taught by the oldest TA has a lower mean quiz score. All groups have different mean quiz scores. All groups have the same mean quiz score. numerator df Enter an exact number. 20 denominator df Enter an exact number. 21 Submit Answer Save Progress Your work in question(s) will also be submitted or saved. Submit Assignment Save Assignment Progress Practice Another Version Viewing Saved Work Revert to Last Response 3. -/0.64 points MIntroStat8 12.E.047. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Question Part Send Points Submissions Used 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 -/0.04 -/0.04 -/0.04 -/0.04 -/0.04 -/0.04 -/0.04 -/0.04 -/0.04 -/0.04 -/0.04 -/0.04 -/0.04 -/0.04 -/0.08 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 Total -/0.64 Many studies have suggested that there is a link between exercise and healthy bones. Exercise stresses the bones and this causes them to get stronger. One study examined the effect of jumping on the bone density of growing rats. There were three treatments: a control with no jumping, a low-jump condition (the jump height was 30 centimeters), and a high-jump condition (60 centimeters). After 8 weeks of 10 jumps per day, 5 days per week, the bone density of the rats (expressed in mg/cm3 ) was measured. Here are the data. data337.dat (a) Make a table giving the sample size, mean, and standard deviation for each group of rats. Consider whether or not it is reasonable to pool the variances. (Round your answers for x, s, and to one decimal place.) Group n s Control Enter an exact number. 1 Low jump Enter an exact number. 5 High jump Enter an exact number. Enter a number. Enter a number. Enter a number. 2 3 4 Enter a number. Enter a number. Enter a number. 6 7 8 Enter a number. Enter a number. Enter a number. 10 9 11 12 (b) Run the analysis of variance. Report the F statistic with its degrees of freedom and P-value. What do you conclude? (Round your test statistic to two decimal places and your P-value to three decimal places.) = Enter a number. F 13 = Enter a P number. 14 ---Select--- Conclusion: There is 15 means at the = .05 level. Submit Answer statistically significant difference between the three treatment Save Progress Your work in question(s) will also be submitted or saved. Submit Assignment Save Assignment Progress Practice Another Version Viewing Saved Work Revert to Last Response 4. -/0.64 points MIntroStat8 12.E.061. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Question Part Points Submissions Used 1 -/0.64 0/5 Send -/0.64 A study of reading comprehension in children compared three methods of instruction. The three methods of instruction are called Basal, DRTA, and Strategies. As is common in such studies, several pretest variables were measured before any instruction was given. One purpose of the pretest was to see if the three groups of children were similar in their comprehension skills. The READING data set described in the Data Appendix gives two pretest measures that were used in this study. Use one-way ANOVA to analyze these data and write a summary of your results. 1 This answer has not been graded yet. Submit Answer Save Progress Your work in question(s) will also be submitted or saved. Submit Assignment Save Assignment Progress Viewing Saved Work Revert to Last Response 5. -/0.64 points MIntroStat8 12.E.062. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Question Part Points Submissions Used 1 -/0.64 0/5 Total -/0.64 Send A study of reading comprehension in children compared three methods of instruction. The three methods of instruction are called Basal, DRTA, and Strategies. Basal is the traditional method of teaching, while DRTA and Strategies are two innovative methods based on similar theoretical considerations. The READING data set includes three response variables that the new methods were designed to improve. Analyze these variables using ANOVA methods. Be sure to include multiple comparisons or contrasts as needed. Write a report summarizing your findings. 1 This answer has not been graded yet. Submit Answer Save Progress Your work in question(s) will also be submitted or saved. Submit Assignment Save Assignment Progress Viewing Saved Work Revert to Last Response 6. -/0.64 points MIntroStat8 12.E.065. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Question Part Points Submissions Used 1 -/0.64 0/5 Total -/0.64 Send Search the Internet or your library to find a study that is interesting to you and that used one-way ANOVA to analyze the data. First describe the question or questions of interest and then give the details of how ANOVA was used to provide answers. Be sure to include how the study authors examined the assumptions for the analysis. Evaluate how well the authors used ANOVA in this study. If your evaluation finds the analysis deficient, make suggestions for how it could be improved. 1 This answer has not been graded yet. Submit Answer Save Progress Your work in question(s) will also be submitted or saved. Submit Assignment Save Assignment Progress Viewing Saved Work Revert to Last Response 7. -/0.64 points MIntroStat8 12.E.501.XP. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Question Part Send Points Submissions Used 1 2 -/0.32 -/0.32 0/5 0/5 The One-Way ANOVA applet lets you see how the F statistic and the P-value depend on the variability of the data within groups and the differences among the means. (a) The black dots are at the means of the three groups. Move these up and down until you get a configuration that gives a P-value of about 0.01. What is the value of the F statistic? 1 This answer has not been graded yet. (b) Now increase the variation within the groups by dragging the mark on the pooled standard error scale to the right. Describe what happens to the F statistic and the P-value. Explain why this happens. 2 This answer has not been graded yet. Submit Answer Save Progress Your work in question(s) will also be submitted or saved. Submit Assignment Save Assignment Progress Viewing Saved Work Revert to Last Response 8. -/0.64 points MIntroStat8 12.E.503.XP. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Question Part Points Submissions Used 1 -/0.64 0/5 Total -/0.64 Send Corporate advertising tries to enhance the image of the corporation. A study compared two ads from two sources, the Wall Street Journal and the National Enquirer. Subjects were asked to pretend that their company was considering a major investment in Performax, the fictitious sportswear firm in the ads. Each subject was asked to respond to the question "How trustworthy was the source in the sportswear company ad for Performax?" on a 7-point scale. Higher values indicated more trustworthiness. Here is a summary of the results. Ad source n x s Wall Street Journal 66 4.77 1.50 National Enquirer 61 2.43 1.64 Find the two-sample pooled t statistic. Then formulate the problem as an ANOVA and report the results of this analysis. Verify that F = t 2. 1 This answer has not been graded yet. Submit Answer Save Progress Your work in question(s) will also be submitted or saved. Submit Assignment Save Assignment Progress Viewing Saved Work Revert to Last Response 9. -/0.64 points MIntroStat8 12.E.504.XP. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Question Part Points Submissions Used 1 2 3 4 -/0.16 -/0.16 -/0.16 -/0.16 Send 0/5 0/5 0/5 0/5 Total -/0.64 A survey looked at the value of recreational sports on college campuses. One of the questions asked each student to rate the importance of recreational sports to college satisfaction and success. Responses were on a 10-point scale with 1 indicating total lack of importance and 10 indicating very high importance. The following table summarizes these results: Class n Mean score Freshman Sophomore Junior Senior 729 535 594 439 7.6 7.6 7.5 7.3 (a) To compare the mean scores across classes, what are the degrees of freedom for the ANOVA F statistic? Enter an exact number. numerator df 1 denominator df Enter an exact number. 2 (b) The MSG = 11.306. If sp = 2.11, what is the F statistic? (Round your answer to two decimal places.) F= Enter a number. 3 (c) Give an approximate (from Table E) or exact (from software) P-value. (Enter your answer to four decimal places.) Enter a number. 4 Submit Answer Save Progress Your work in question(s) will also be submitted or saved. Save Assignment Progress Submit Assignment Save Assignment Progress Practice Another Version Viewing Saved Work Revert to Last Response 10. -/0.64 points MIntroStat8 12.E.506.XP. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Question Part Send Points Submissions Used 1 2 3 4 5 6 7 8 9 10 11 12 13 14 -/0.04 -/0.04 -/0.04 -/0.04 -/0.04 -/0.04 -/0.04 -/0.04 -/0.04 -/0.04 -/0.04 -/0.04 -/0.04 -/0.12 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 Total -/0.64 Different varieties of the tropical flower Heliconia are fertilized by different species of hummingbirds. Over time, the lengths of the flowers and the form of the hummingbirds' beaks have evolved to match each other. Here are data on the lengths in millimeters of three varieties of these flowers on the island of Dominica. data354.dat Do a complete analysis that includes description of the data and a significance test to compare the mean lengths of the flowers for the three species. (Round your answers for x to four decimal places, s to three decimal places, and to three decimal places. Round your test statistic to two decimal places. Round your P-value to three decimal places.) flower type n s H. bihai Enter an exact number. 1 Enter a number. Enter a number. Enter a number. 2 3 4 H. caribaea red Enter an exact number. 5 H. caribaea yellow Enter an exact number. Enter a number. Enter a number. Enter a number. 6 7 8 Enter a number. Enter a number. Enter a number. 10 11 9 F= Enter a number. 13 P= Enter a number. 14 Submit Answer Save Progress Your work in question(s) will also be submitted or saved. Submit Assignment Save Assignment Progress Practice Another Version Viewing Saved Work Revert to Last Response 11. -/0.64 points MIntroStat8 12.E.508.XP. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Question Part Points Submissions Used 1 2 -/0.32 -/0.32 Send 12 0/5 0/5 Total -/0.64 Do piano lessons improve the spatial-temporal reasoning of preschool children? The data in the table below contain the change in spatial-temporal reasoning (after treatment minus before treatment) of 34 children who took piano lessons, 10 who took singing lessons, 20 who had some computer instruction, and 14 who received no extra lessons. (a) Make a table giving the sample size, the mean, the standard deviation, and the standard error for each group. 1 This answer has not been graded yet. (b) Analyze the data using one-way analysis of variance. State the null and alternative hypotheses, the test statistic with degrees of freedom, the P-value, and your conclusion. 2 This answer has not been graded yet. Submit Answer Save Progress Your work in question(s) will also be submitted or saved. Submit Assignment Save Assignment Progress Viewing Saved Work Revert to Last Response 12. -/0.64 points MIntroStat8 12.E.509.XP. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Question Part Send Points Submissions Used 1 -/0.64 0/5 Do piano lessons improve the spatial-temporal reasoning of preschool children? This question was examined by comparing the change scores (after treatment minus before treatment) of 34 children who took piano lessons with the scores of 44 children who did not. The latter group actually contained three groups of children: 10 were given singing lessons, 20 had some computer instruction, and 14 received no extra lessons. The data appear in Table 12.4. Use the Bonferroni or another multiple comparisons procedure to compare the group means. Summarize the results and support your conclusions. 1 This answer has not been graded yet. Submit Answer Save Progress Your work in question(s) will also be submitted or saved. Submit Assignment Save Assignment Progress Viewing Saved Work Revert to Last Response 13. -/0.64 points MIntroStat8 12.E.511.XP. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Send Question Part Points Submissions Used 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 -/0.04 -/0.04 -/0.04 -/0.04 -/0.04 -/0.04 -/0.04 -/0.04 -/0.04 -/0.04 -/0.04 -/0.04 -/0.04 -/0.04 -/0.08 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 Total -/0.64 Iron-deficiency anemia is the most common form of malnutrition in developing countries, affecting about 50% of children and women and 25% of men. Iron pots for cooking foods had traditionally been used in many of these countries, but they have been largely replaced by aluminum pots, which are cheaper and lighter. Some research has suggested that food cooked in iron pots will contain more iron than food cooked in other types of pots. One study designed to investigate this issue compared the iron content of some Ethiopian foods cooked in aluminum, clay, and iron pots. One of the foods was yesiga wet, beef cut into small pieces and prepared with several Ethiopian spices. The iron content of four samples of yesiga wet cooked in each of the three types of pots is given below. The units are milligrams of iron per 100 grams of cooked food. data265.dat (a) Make a table giving the sample size, mean, and standard deviation for each type of pot. Is it reasonable to pool the variances? Note that with the small sample sizes in this experiment, we expect a large amount of variability in the sample standard deviations. Type of pot n s Aluminum Enter an exact number. 1 Clay Enter an exact number. 5 Iron Enter an exact number. Enter a number. Enter a number. Enter a number. 2 3 4 Enter a number. Enter a number. Enter a number. 6 7 8 Enter a number. Enter a number. Enter a number. 10 11 12 9 (b) Run the analysis of variance. Report the F statistic with its degrees of freedom and P-value. What do you conclude? (Round your test statistic to two decimal places. Round your P-value to three decimal places.) F= Enter a number. 13 P= Enter a number. 14 ---Select--- Conclusion: There is 15 means at the = .05 level. Submit Answer statistically significant difference between the three treatment Save Progress Your work in question(s) will also be submitted or saved. Submit Assignment Save Assignment Progress Practice Another Version Viewing Saved Work Revert to Last Response 14. -/0.64 points MIntroStat8 12.E.514.XP. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Question Part Points Submissions Used 1 -/0.64 0/5 Total -/0.64 Send Kudzu is a plant that was imported to the United States from Japan and now covers over seven million acres in the South. The plant contains chemicals called isoflavones that have been shown to have beneficial effects on bones. One study used three groups of rats to compare a control group with rats that were fed either a low dose or a high dose of isoflavones from kudzu. One of the outcomes examined was the bone mineral density in the femur (in grams per square centimeter). Here are the data. Treatment Bone mineral density (g/cm2) Control 0.228 0.207 0.234 0.220 0.217 0.228 0.209 0.221 0.204 0.220 0.203 0.219 0.218 0.245 0.210 Low dose 0.211 0.220 0.211 0.233 0.219 0.233 0.226 0.228 0.216 0.225 0.200 0.208 0.198 0.208 0.203 High dose 0.250 0.237 0.217 0.206 0.247 0.228 0.245 0.232 0.267 0.261 0.221 0.219 0.232 0.209 0.255 In this study there were three groups. Controls received a placebo, and the other two groups received either a low or a high dose of isoflavones from kudzu. You are planning a similar study of a new kind of isoflavone. Use the results of the study above to plan your study. Write a proposal explaining why your study should be funded. 1 This answer has not been graded yet. Submit Answer Save Progress Your work in question(s) will also be submitted or saved. Submit Assignment Save Assignment Progress Viewing Saved Work Revert to Last Response 15. -/0.64 points MIntroStat8 13.E.027. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Question Part Points Send Submissions Used 1 2 3 4 5 6 7 8 -/0.08 -/0.08 -/0.08 -/0.08 -/0.08 -/0.08 -/0.08 -/0.08 0/5 0/5 0/5 0/5 0/5 0/5 0/5 0/5 Total -/0.64 The National Crime Victimization Survey estimates that there were over 400,000 violent crimes committed against women by their intimate partner that resulted in physical injury. An intervention study designed to increase safety behaviors of abused women compared the effectiveness of six telephone intervention sessions with a control group of abused women who received standard care. Fifteen different safety behaviors were examined. One of the variables analyzed was the total number of behaviors (out of 15) that each woman performed. Here is a summary of the means of this variable at baseline (just before the first telephone call) and at follow-up 3 and 6 months later. Time Group Baseline 3 months 6 months Intervention 10.4 12.5 11.9 Control 9.6 9.9 10.4 (a) Find the marginal means. (Round your answers to three decimal places.) Time Group Intervention Baseline 10.4 3 months 12.5 6 months 11.9 Mean Enter a number. 1 Control 9.6 9.9 10.4 Enter a number. 2 Mean Enter a number. Enter a number. Enter a number. Enter a number. 3 4 5 6 Are they useful for understanding the results of this study? The row means suggest that the intervention group showed less improvement than the control group. The row means suggest that the control group showed more improvement than the baseline group. The row means suggest that the intervention group showed more improvement than the 6 months group. The row means suggest that the control group showed more improvement than the 3 months group. The row means suggest that the intervention group showed more improvement than the control group. (b) Plot the means. Do you think there is an interaction? Describe the meaning of an interaction for this study. Yes there is an interaction, it means that the mean number of actions does not change over time for the two groups. Yes there is an interaction, it means that the mean number of actions changes differently over time for the two groups. Yes there is an interaction, it means that the mean number of actions changes consistently over time for the two groups. No there is not an interaction, meaning that the mean number of actions does not change over time for the two groups. (Note: This exercise is from a repeated-measures design, and the data are not particularly normal because they are counts with values from 1 to 10. Although we cannot use the methods in this chapter for statistical inference in this setting, the example does illustrate ideas about interactions.) Submit Answer Save Progress Your work in question(s) will also be submitted or saved. Submit Assignment Save Assignment Progress Practice Another Version Viewing Saved Work Revert to Last Response 16. -/0.64 points MIntroStat8 13.E.033. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Question Part Points Submissions Used 1 2 -/0.32 -/0.32 Send 0/5 0/5 Total -/0.64 The amount of chromium in the diet has an effect on the way the body processes insulin. In an experiment designed to study this phenomenon, four diets were fed to male rats. There were two factors. Chromium had two levels: low (L) and normal (N). The rats were allowed to eat as much as they wanted (M) or the total amount that they could eat was restricted (R). We call the second factor Eat. One of the variables measured was the amount of an enzyme called GITH. The means for this response variable appear in the following table. Eat Chromium M R L 4.545 5.175 N 4.425 5.317 A plot of the mean GITH for these diets, with the factor Chromium on the x axis and GITH on the y axis is given below. For each Eat group the points for the two Chromium means are connected. (a) Describe the patterns you see. Does the amount of chromium in the diet appear to affect the GITH mean? Does restricting the diet rather than letting the rats eat as much as they want appear to have an effect? Is there an interaction? 1 This answer has not been graded yet. (b) Compute the marginal means. Compute the differences between the M and R diets for each level of Chromium. Use this information to summarize numerically the patterns in the plot. 2 This answer has not been graded yet. Submit Answer Save Progress Your work in question(s) will also be submitted or saved. Submit Assignment Save Assignment Progress Viewing Saved Work Revert to Last Response 17. -/0.64 points MIntroStat8 13.E.036. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Question Part Send Points Submissions Used 1 2 3 -/0.21 -/0.21 -/0.22 0/5 0/5 0/5 Iron-deficiency anemia is the most common form of malnutrition in developing countries, affecting about 50% of children and women and 25% of men. Iron pots for cooking foods had traditionally been used in many of these countries, but they have been largely replaced by aluminum pots, which are cheaper and lighter. Some research has suggested that food cooked in iron pots will contain more iron than food cooked in other types of pots. One study designed to investigate this issue compared the iron content of some Ethiopian foods cooked in aluminum, clay, and iron pots. Foods considered were yesiga wet', beef cut into small pieces and prepared with several Ethiopian spices; shiro wet', a legume-based mixture of chickpea flour and Ethiopian spiced pepper; and ye-atkilt allych'a, a lightly spiced vegetable casserole. Four samples of each food were cooked in each type of pot. The iron in the food is measured in milligrams of iron per 100 grams of cooked food. The data are shown in the table below. Iron Content (mg/100 g) of Food Cooked in Different Pots Type of pot Meat Legumes Vegetables Aluminum 1.77 2.36 1.96 2.14 2.40 2.17 2.41 2.34 1.03 1.53 1.07 1.30 Clay 2.27 1.28 2.48 2.68 2.41 2.43 2.57 2.48 1.55 0.79 1.68 1.82 Iron 5.27 5.17 4.06 4.22 3.69 3.43 3.84 3.72 2.45 2.99 2.80 2.92 (a) Make a table giving the sample size, mean, and standard deviation for each type of pot. Is it reasonable to pool the variances? Although the standard deviations vary more than we would like, this is partially due to the small sample sizes, and we will proceed with the analysis of variance. 1 This answer has not been graded yet. (b) Plot the means. Give a short summary of how the iron content of foods depends upon the cooking pot. 2 This answer has not been graded yet. (c) Run the analysis of variance. Give the ANOVA table, the F statistics with degrees of freedom and Pvalues, and your conclusions regarding the hypotheses about main effects and interactions. 3 This answer has not been graded yet. Submit Answer Save Progress Your work in question(s) will also be submitted or saved. Submit Assignment Save Assignment Progress Viewing Saved Work Revert to Last Response 18. -/0.64 points MIntroStat8 13.E.039. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Question Part Points Send Submissions Used 1 2 3 4 -/0.16 -/0.16 -/0.16 -/0.16 0/5 0/5 0/5 0/5 Total -/0.64 One step in the manufacture of large engines requires that holes of very precise dimensions be drilled. The tools that do the drilling are regularly examined and are adjusted to ensure that the holes meet the required specifications. Part of the examination involves measurement of the diameter of the drilling tool. A team studying the variation in the sizes of the drilled holes selected this measurement procedure as a possible cause of variation in the drilled holes. They decided to use a designed experiment as one part of this examination. Some of the data are given in the table below. The diameters in millimeters (mm) of five tools were measured by the same operator at three times (8:00 A.M., 11:00 A.M., and 3:00 P.M.). Three measurements were taken on each tool at each time. The person taking the measurements could not tell which tool was being measured, and the measurements were taken in random order. (a) Make a table of means and standard deviations for each of the 5 3 combinations of the two factors. 1 This answer has not been graded yet. (b) Plot the means and describe how the means vary with tool and time. Note that we expect the tools to have slightly different diameters. These will be adjusted as needed. It is the process of measuring the diameters that is important. 2 This answer has not been graded yet. (c) Use a two-way ANOVA to analyze these data. Report the test statistics, degrees of freedom, and Pvalues for the significance tests. 3 This answer has not been graded yet. (d) Write a short report summarizing your results. 4 This answer has not been graded yet. Submit Answer Save Progress Your work in question(s) will also be submitted or saved. Submit Assignment Save Assignment Progress Viewing Saved Work Revert to Last Response 19. -/0.64 points MIntroStat8 13.E.040. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Question Part Points Submissions Used 1 -/0.64 0/5 Total -/0.64 Send One step in the manufacture of large engines requires that holes of very precise dimensions be drilled. The tools that do the drilling are regularly examined and are adjusted to ensure that the holes meet the required specifications. Part of the examination involves measurement of the diameter of the drilling tool. A team studying the variation in the sizes of the drilled holes selected this measurement procedure as a possible cause of variation in the drilled holes. They decided to use a designed experiment as one part of this examination. Some of the data are given in the table below. The diameters in millimeters (mm) of five tools were measured by the same operator at three times (8:00 A.M., 11:00 A.M., and 3:00 P.M.). Three measurements were taken on each tool at each time. The person taking the measurements could not tell which tool was being measured, and the measurements were taken in random order. Multiply each measurement by 0.04 to convert from millimeters to inches. Plot the means and run a twoway ANOVA using the transformed measurements. Summarize what parts of the analysis have changed and what parts have remained the same. 1 This answer has not been graded yet. Submit Answer Save Progress Your work in question(s) will also be submitted or saved. Submit Assignment Save Assignment Progress Viewing Saved Work Revert to Last Response 20. -/0.64 points MIntroStat8 13.E.041. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Question Part Points Submissions Used 1 2 -/0.32 -/0.32 0/5 0/5 Send Total -/0.64 Do left-handed people live shorter lives than right-handed people? A study of this question examined a sample of 949 death records and contacted next of kin to determine handedness. Note that there are many possible definitions of "left-handed." The researchers examined the effects of different definitions on the results of their analysis and found that their conclusions were not sensitive to the exact definition used. For the results presented here, people were defined to be right-handed if they wrote, drew, and threw a ball with the right hand. All others were defined to be left-handed. People were classified by gender (female or male) and handedness (left or right), and a 2 2 ANOVA was run with the age at death as the response variable. The F statistics were 22.36 (handedness), 37.44 (gender), and 2.10 (interaction). The following marginal mean ages at death (in years) were reported: 77.39 (females), 71.32 (males), 75.00 (right-handed), and 66.03 (left-handed). (a) For each of the F statistics given, find the degrees of freedom and an approximate P-value. Summarize the results of these tests. 1 This answer has not been graded yet. (b) Using the information given, write a short summary of the results of the study. 2 This answer has not been graded yet. Submit Answer Save Progress Your work in question(s) will also be submitted or saved. Submit Assignment Save Assignment Progress Viewing Saved Work Revert to Last Response 21. -/0.64 points MIntroStat8 13.E.044. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Question Part Send Points Submissions Used 1 -/0.64 0/5 The PLANTS1 data set in the Data Appendix gives the percent of nitrogen in four different species of plants grown in a laboratory. The species are Leucaena leucocephala, Acacia saligna, Prosopis juliflora, and Eucalyptus citriodora. The researchers who collected these data were interested in commercially growing these plants in parts of the country of Jordan where there is very little rainfall. To examine the effect of water, they varied the amount per day from 50 millimeters (mm) to 650 mm in 100 mm increments. There were nine plants per species-by-water combination. Because the plants are to be used primarily for animal food, with some parts that can be consumed by people, a high nitrogen content is very desirable. Examine the residuals. Are there any unusual patterns or outliers? If you think that there are one or more points that are somewhat extreme, rerun the two-way analysis without these observations. Does this change the results in any substantial way? 1 This answer has not been graded yet. Submit Answer Save Progress Your work in question(s) will also be submitted or saved. Submit Assignment Save Assignment Progress Viewing Saved Work Revert to Last Response 22. -/0.64 points MIntroStat8 13.E.046. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Send Question Part Points Submissions Used 1 -/0.64 0/5 The PLANTS1 data set in the Data Appendix gives the percent of nitrogen in four different species of plants grown in a laboratory. The species are Leucaena leucocephala, Acacia saligna, Prosopis juliflora, and Eucalyptus citriodora. The researchers who collected these data were interested in commercially growing these plants in parts of the country of Jordan where there is very little rainfall. To examine the effect of water, they varied the amount per day from 50 millimeters (mm) to 650 mm in 100 mm increments. There were nine plants per species-by-water combination. Because the plants are to be used primarily for animal food, with some parts that can be consumed by people, a high nitrogen content is very desirable. Run a separate one-way analysis of variance for each species and summarize the results. Since the amount of water is a quantitative factor, we can also analyze these data using regression. Run simple linear regressions separately for each species to predict nitrogen percent from water. Use plots to determine whether or not a line is a good way to approximate this relationship. Summarize the regression results and compare them with the one-way ANOVA results. 1 This answer has not been graded yet. Submit Answer Save Progress Your work in question(s) will also be submitted or saved. Submit Assignment Save Assignment Progress Viewing Saved Work Revert to Last Response 23. -/0.64 points MIntroStat8 13.E.048. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Question Part Send Points Submissions Used 1 -/0.64 0/5 The PLANTS2 data file gives data on four different species of plants grown in a laboratory. The species are Leucaena leucocephala, Acacia saligna, Prosopis juliflora, and Eucalyptus citriodora. The researchers who collected these data were interested in commercially growing these plants in parts of the country of Jordan where there is very little rainfall. To examine the effect of water, they varied the amount per day from 50 millimeters (mm) to 650 mm in 100 mm increments. There were four plants per speciesby-water combination. There are two response variables. They are fresh biomass and dry biomass. High values for both of these variables are desirable. Examine the residuals for the two response variables. Are there any unusual patterns or outliers? If you think that there are one or more points that are somewhat extreme, rerun the two-way analysis without these observations. Does this change the results in any substantial way? 1 This answer has not been graded yet. Submit Answer Save Progress Your work in question(s) will also be submitted or saved. Submit Assignment Save Assignment Progress Viewing Saved Work Revert to Last Response 24. -/0.64 points MIntroStat8 13.E.049. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Question Part Send Points Submissions Used 1 -/0.64 0/5 The PLANTS2 data file gives data on four different species of plants grown in a laboratory. The species are Leucaena leucocephala, Acacia saligna, Prosopis juliflora, and Eucalyptus citriodora. The researchers who collected these data were interested in commercially growing these plants in parts of the country of Jordan where there is very little rainfall. To examine the effect of water, they varied the amount per day from 50 millimeters (mm) to 650 mm in 100 mm increments. There were four plants per speciesby-water combination. There are two response variables. They are fresh biomass and dry biomass. High values for both of these variables are desirable. Run a separate one-way analysis of variance for both response variables for each water level. If there is evidence that the species are not all the same, use a multiple comparisons procedure to determine which pairs of species are significantly different. In what way, if any, do the differences appear to vary by water level? Write a short summary of your conclusions. 1 This answer has not been graded yet. Submit Answer Save Progress Your work in question(s) will also be submitted or saved. Submit Assignment Save Assignment Progress Viewing Saved Work Revert to Last Response 25. -/0.64 points MIntroStat8 13.E.050. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Question Part Send Points Submissions Used 1 -/0.64 0/5 The PLANTS2 data file gives data on four different species of plants grown in a laboratory. The species are Leucaena leucocephala, Acacia saligna, Prosopis juliflora, and Eucalyptus citriodora. The researchers who collected these data were interested in commercially growing these plants in parts of the country of Jordan where there is very little rainfall. To examine the effect of water, they varied the amount per day from 50 millimeters (mm) to 650 mm in 100 mm increments. There were four plants per speciesby-water combination. There are two response variables. They are fresh biomass and dry biomass. High values for both of these variables are desirable. Run a separate one-way analysis of variance for both response variables for each species and summarize the results. Since the amount of water is a quantitative factor, we can also analyze these data using regression. Run simple linear regressions separately for both response variables for each species. Use plots to determine whether or not a line is a good way to approximate this relationship. Summarize the regression results and compare them with the one-way ANOVA results. 1 This answer has not been graded yet. Submit Answer Save Progress Your work in question(s) will also be submitted or saved. Submit Assignment Save Assignment Progress Viewing Saved Work Revert to Last Response 26. -/0.64 points MIntroStat8 13.E.052. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Question Part Send Points Submissions Used 1 -/0.64 0/5 Refer to the data given for the change-of-majors study in the data file MAJORS. Consider gender and whether students changed majors as the two factors. Analyze the data for HSS, the high school science grades. Your analysis should include a table of sample sizes, means, and standard deviations; Normal quantile plots; a plot of the means; and a two-way ANOVA using sex and major as the factors. Write a short summary of your conclusions. 1 This answer has not been graded yet. Submit Answer Save Progress Your work in question(s) will also be submitted or saved. Submit Assignment Save Assignment Progress Viewing Saved Work Revert to Last Response 27. -/0.64 points MIntroStat8 13.E.054. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Question Part Send Points Submissions Used 1 -/0.64 0/5 Refer to the data given for the change-of-majors study in the data file MAJORS. Consider gender and whether students changed majors as the two factors. Analyze the data for GPA, the college grade point average. Your analysis should include a table of sample sizes, means, and standard deviations; Normal quantile plots; a plot of the means; and a two-way ANOVA using sex and major as the factors. Write a short summary of your conclusions. 1 This answer has not been graded yet. Submit Answer Save Progress Your work in question(s) will also be submitted or saved. Submit Assignment Save Assignment Progress Viewing Saved Work Revert to Last Response 28. -/0.64 points MIntroStat8 13.E.056. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Question Part Points Submissions Used Send 1 -/0.64 0/5 Search the Internet or your library to find a study that is interesting to you and uses a two-way ANOVA to analyze data. First describe the question or questions of interest and then give the details of how ANOVA was used to provide answers. Be sure to include how the study authors examined the assumptions for the analysis. Evaluate how well the authors used ANOVA in this study. If your evaluation finds the analysis deficient, make suggestions for how it could be improved. 1 This answer has not been graded yet. Submit Answer Save Progress Your work in question(s) will also be submitted or saved. Submit Assignment Save Assignment Progress Viewing Saved Work Revert to Last Response 29. -/0.64 points MIntroStat8 13.E.515.XP. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Question Part Points Submissions Used 1 -/0.64 0/5 Send Total -/0.64 A study of undergraduate computer science students examined changes in major after the first year. The study examined the fates of 256 students who enrolled as first-year students in the same fall semester. The students were classified according to gender and their declared major at the beginning of the second year. For convenience we use the labels CS for computer science majors, EO for engineering and other science majors, and O for other majors. The explanatory variables included several high school grade summaries coded as 10 = A, 9 = A-, etc. Here are the mean high school mathematics grades for these students. Major Gender CS Males EO O 8.68 8.35 7.65 Females 9.11 9.36 8.04 Describe the main effects and interaction using appropriate graphs and calculations. 1 This answer has not been graded yet. Submit Answer Save Progress Your work in question(s) will also be submitted or saved. Submit Assignment Save Assignment Progress Viewing Saved Work Revert to Last Response 30. -/0.64 points MIntroStat8 13.E.516.XP. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Question Part Points Submissions Used Send 1 -/0.64 0/5 A study of undergraduate computer science students examined changes in major after the first year. The study examined the fates of 256 students who enrolled as first-year students in the same fall semester. The students were classified according to gender and their declared major at the beginning of the second year. For convenience we use the labels CS for computer science majors, EO for engineering and other science majors, and O for other majors. The mean SAT mathematics scores for the students are summarized in the following table. Major Gender CS EO Males O 628 618 589 Females 582 631 543 Summarize the results of this study using appropriate plots and calculations to describe the main effects and interaction. 1 This answer has not been graded yet. Submit Answer Save Progress Your work in question(s) will also be submitted or saved. Submit Assignment Save Assignment Progress Viewing Saved Work Revert to Last Response 31. -/0.8 points MIntroStat8 13.E.517.XP. Ask Your Teacher Sent My Notes {{message.from}} Me {{message.createdAt | date:'EEEE, MMM dd, h:mma'}} {{message.body}} No response yet There was an error sending your message. Ask Your Teacher Question Part Send Points Submissions Used 1 -/0.8 0/5 A study of undergraduate computer science students examined changes in major after the first year. The study examined the fates of 256 students who enrolled as first-year students in the same fall semester. The students were classified according to gender and their declared major at the beginning of the second year. The students studied were enrolled at a large Midwestern university several years ago. Discuss how you would conduct a similar study at a college or university of your choice today. Include a description of all variables that you would collect for your study. 1 This answer has not been graded yet. Submit Answer Save Progress Your work in question(s) will also be submitted or saved. Submit Assignment Save Assignment Progress Viewing Saved Work Revert to Last Response Submit Assignment Save Assignment Progress Home My Assignments Extension Request WebAssign 4.0 1997-2016 Advanced Instructional Systems, Inc. All rights reserved