1 of 40 0.0/ 2.5 Points A researcher wants to check the claim that convicted burglars spend an average of 18.7 months in jail. She takes a random sample of 35 such cases from court files and finds that months. Assume that the population standard deviation is 7 months. Test the null hypothesis that = 18.7 at the 0.05 significance level. A. Do not reject the null hypothesis and conclude that the claim that the mean is different from 18.7 months is supported. B. Do not reject the null hypothesis and conclude that the claim that the mean is different from 18.7 months cannot be supported. C. Reject the null hypothesis and conclude that the claim that the mean is different from 18.7 months is supported. D. Reject the null hypothesis and conclude that the claim that the mean is different from 18.7 months cannot be supported. Question 2 of 40 0.0/ 2.5 Points The owner of a football team claims that the average attendance at home games is over 3000, and he is therefore justified in moving the team to a city with a larger stadium. Assuming that a hypothesis test of the claim has been conducted and that the conclusion is failure to reject the null hypothesis, state the conclusion in non-technical terms. A. There is sufficient evidence to support the claim that the mean attendance is greater than 3000. B. There is sufficient evidence to support the claim that the mean attendance is equal to 3000. C. There is not sufficient evidence to support the claim that the mean attendance is greater than 3000. D. There is not sufficient evidence to support the claim that the mean attendance is less than 3000. Question 3 of 40 2.5/ 2.5 Points At one school, the mean amount of time that tenth-graders spend watching television each week is 18.4 hours. The principal introduces a campaign to encourage the students to watch less television. One year later, the principal wants to perform a hypothesis test to determine whether the average amount of time spent watching television per week has decreased. Formulate the null and alternative hypotheses for the study described. A. Ho: = 18.4 hours H a : 18.4 hours B. Ho: = 18.4 hours H a : < 18.4 hours C. Ho: 18.4 hours H a : < 18.4 hours D. Ho: = 18.4 hours H a : > 18.4 hours Question 4 of 40 0.0/ 2.5 Points A nationwide study of American homeowners revealed that 65% have one or more lawn mowers. A lawn equipment manufacturer, located in Omaha, feels the estimate is too low for households in Omaha. Find the P-value for a test of the claim that the proportion with lawn mowers in Omaha is higher than 65%. Among 497 randomly selected homes in Omaha, 340 had one or more lawn mowers. Use Table 5.1 to find the best answer. A. 0.0559 B. 0.1118 C. 0.0252 D. 0.0505 Question 5 of 40 2.5/ 2.5 Points A consumer group claims that the mean running time for a certain type of flashlight battery is not the same as the manufacturers claims. Determine the null and alternative hypotheses for the test described. A. H0: = Manufacturers claims Ha: < Manufacturers claims B. H0: = Manufacturers claims Ha: Manufacturers claims C. H0: = Manufacturers claims Ha: > Manufacturers claims D. H0: Manufacturers claims Ha: = Manufacturers claims Question 6 of 40 2.5/ 2.5 Points A skeptical paranormal researcher claims that the proportion of Americans that have seen a UFO is less than 1 in every one thousand. State the null hypothesis and the alternative hypothesis for a test of significance. A. H0: p = 0.001 Ha: p > 0.001 B. H0: p = 0.001 Ha: p < 0.001 C. H0: p > 0.001 Ha: p = 0.001 D. H0: p < 0.001 Ha: p = 0.001 Question 7 of 40 0.0/ 2.5 Points A two-tailed test is conducted at the 0.10 significance level. What is the P-value required to reject the null hypothesis? A. Greater than or equal to .010 B. Greater than or equal to 0.05 C. Less than or equal to 0.10 D. Less than or equal to 0.05 Question 8 of 40 2.5/ 2.5 Points A two-tailed test is conducted at the 5% significance level. What is the P-value required to reject the null hypothesis? A. Greater than or equal to 0.10 B. Less than or equal to 0.05 C. Less than or equal to 0.10 D. Greater than or equal to 0.05 Question 9 of 40 2.5/ 2.5 Points The owner of a football team claims that the average attendance at home games is over 4000, and he is therefore justified in moving the team to a city with a larger stadium. Assume that a hypothesis test of the claim has been conducted and that the conclusion of the test was to reject the null hypothesis. Identify the population to which the results of the test apply. A. All games played by the team in question in which the attendance is over 4000 B. All future home games to be played by the team in question C. All home games played by the team in question D. None of the populations given are appropriate Question 10 of 40 2.5/ 2.5 Points A study of a brand of in the shell peanuts gives the following results: A significant event at the 0.01 level is a fan getting a bag with how many peanuts? A. 30 peanuts B. 25 or 30 peanuts C. 25 or 55 peanuts D. 25, 30 or 55 peanuts Question 11 of 40 0.0/ 2.5 Points A long-distance telephone company claims that the mean duration of long-distance telephone calls originating in one town was greater than 9.4 minutes, which is the average for the state. Determine the conclusion of the hypothesis test assuming that the results of the sampling do not lead to rejection of the null hypothesis. A. Conclusion: Support the claim that the mean is less than 9.4 minutes. B. Conclusion: Support the claim that the mean is greater than 9.4 minutes. C. Conclusion: Support the claim that the mean is equal to 9.4 minutes. D. Conclusion: Do not support the claim that the mean is greater than 9.4 minutes. Question 12 of 40 2.5/ 2.5 Points In 1990, the average duration of long-distance telephone calls originating in one town was 9.3 minutes. A long-distance telephone company wants to perform a hypothesis test to determine whether the average duration of long-distance phone calls has changed from the 1990 mean of 9.3 minutes. Formulate the null and alternative hypotheses for the study described. A. Ho: = 9.3 minutes H a : < 9.3 minutes B. Ho: = 9.3 minutes H a : > 9.3 minutes C. Ho: = 9.3 minutes H a : 9.3 minutes D. Ho: 9.3 minutes H a : = 9.3 minutes Question 13 of 40 0.0/ 2.5 Points If a fan purchased a bag with 30 peanuts, what is the lowest level at which this would be a significant event? A. 0.05 B. 0.025 C. 0.01 D. It is not significant at any of the levels given Question 14 of 40 2.5/ 2.5 Points A psychologist claims that more than 29 percent of the professional population suffers from problems due to extreme shyness. Assuming that a hypothesis test of the claim has been conducted and that the conclusion is failure to reject the null hypothesis, state the conclusion in non-technical terms. A. There is sufficient evidence to support the claim that the true proportion is less than 29 percent. B. There is not sufficient evidence to support the claim that the true proportion is greater than 29 percent. C. There is sufficient evidence to support the claim that the true proportion is equal to 29 percent. D. There is sufficient evidence to support the claim that the true proportion is greater than 29 percent. Question 15 of 40 0.0/ 2.5 Points A two-tailed test is conducted at the 5% significance level. Which of the z-scores below is the smallest one that leads to rejection of the null hypothesis? A. 1.12 B. 1.48 C. 1.84 D. 2.15 Question 16 of 40 0.0/ 2.5 Points In 1990, the average duration of long-distance telephone calls originating in one town was 9.4 minutes. A long-distance telephone company wants to perform a hypothesis test to determine whether the average duration of long-distance phone calls has changed from the 1990 mean of 9.4 minutes. The mean duration for a random sample of 50 calls originating in the town was 8.6 minutes. Does the data provide sufficient evidence to conclude that the mean call duration, , is different from the 1990 mean of 9.4 minutes? Perform the appropriate hypothesis test using a significance level of 0.01. Assume that s = 4.8 minutes. A. With a z of -1.2 there is sufficient evidence to conclude that the mean value has changed from the 1990 mean of 9.4 minutes. B. With a P-value of 0.2302 there is not sufficient evidence to conclude that the mean value is less than the 1990 mean of 9.4 minutes. C. With a P-value of 0.2302 there is sufficient evidence to conclude that the mean value is less than the 1990 mean of 9.4 minutes. D. With a z of 1.2 there is not sufficient evidence to conclude that the mean value has changed from the 1990 mean of 9.4 minutes. Question 17 of 40 0.0/ 2.5 Points A researcher claims that the amounts of acetaminophen in a certain brand of cold tablets have a mean different from the 600 mg claimed by the manufacturer. Test this claim at the 0.02 level of significance. The mean acetaminophen content for a random sample of n = 41 tablets is 603.3 mg. Assume that the population standard deviation is 4.9 mg. A. Since the test statistic is greater than the critical z, there is sufficient evidence to accept the null hypothesis and to support the claim that the mean content of acetaminophen is 600 mg. B. Since the test statistic is greater than the critical z, there is sufficient evidence to reject the null hypothesis and to support the claim that the mean content of acetaminophen is not 600 mg. C. Since the test statistic is less than the critical z, there is sufficient evidence to reject the null hypothesis and to support the claim that the mean content of acetaminophen is not 600 mg. D. Since the test statistic is greater than the critical z, there is insufficient evidence to reject the null hypothesis and to support the claim that the mean content of acetaminophen is not 600 mg. Question 18 of 40 2.5/ 2.5 Points A two-tailed test is conducted at the 5% significance level. What is the left tail percentile required to reject the null hypothesis? A. 97.5% B. 5% C. 2.5% D. 95% Question 19 of 40 0.0/ 2.5 Points A consumer advocacy group claims that the mean amount of juice in a 16 ounce bottled drink is not 16 ounces, as stated by the bottler. Determine the conclusion of the hypothesis test assuming that the results of the sampling lead to rejection of the null hypothesis. A. Conclusion: Support the claim that the mean is equal to 16 ounces. B. Conclusion: Support the claim that the mean is greater than 16 ounces. C. Conclusion: Support the claim that the mean is not equal to 16 ounces. D. Conclusion: Support the claim that the mean is less than 16 ounces. Question 20 of 40 2.5/ 2.5 Points The principal of a middle school claims that annual incomes of the families of the seventh-graders at his school vary more than the annual incomes of the families of the seventh-graders at a neighboring school, which have variation described by s = $13,700. Assume that a hypothesis test of the claim has been conducted and that the conclusion of the test was to reject the null hypothesis. Identify the population to which the results of the test apply. A. The current seventh graders at the principals school B. Seventh graders families at the school with a standard deviation of $13,700 C. All of the families of the class of seventh graders at the principals school D. All seventh graders families Part 2 of 2 - 20.0/ 50.0 Points Question 21 of 40 0.0/ 2.5 Points A golfer wished to find a ball that would travel more than 160 yards when hit with his 7-iron with a club speed of 90 miles per hour. He had a golf equipment lab test a low compression ball by having a robot swing his club 8 times at the required speed. State the null and alternative hypotheses for this test. A. H0: = 160; Ha: > 150 B. H0: = 150; Ha: > 150 C. H0: = 160; Ha: > 160 D. H0: = 140; Ha: > 160 Question 22 of 40 2.5/ 2.5 Points A golfer wished to find a ball that would travel more than 180 yards when hit with his 5-iron with a club speed of 90 miles per hour. He had a golf equipment lab test a low compression ball by having a robot swing his club 7 times at the required speed. State the null and alternative hypotheses for this test. A. H0: = 180; Ha: > 180 B. H0: > 180; Ha: > 180 C. H0: < 180; Ha: > 180 D. H0: = 180; Ha: < 180 Question 23 of 40 2.5/ 2.5 Points A 95% confidence interval for the mean of a normal population is found to be 13.2 < < 22.4. What is the margin of error? A. 4.6 B. 4.4 C. 4.2 D. 5.6 Question 24 of 40 2.5/ 2.5 Points A golfer wished to find a ball that would travel more than 160 yards when hit with his 7-iron with a club speed of 90 miles per hour. He had a golf equipment lab test a low compression ball by having a robot swing his club 8 times at the required speed. Data from this test resulted in a sample mean of 163.2 yards with a sample standard deviation of 5.8 yards. Assuming normality, carry out a hypothesis test at the 0.05 significance level to determine whether the ball meets the golfers requirements. Use the partial t-table below to solve this problem. Area in one tail 0.025 0.05 Area in two tails Degrees of Freedom n - 1 0.05 0.10 6 2.447 1.943 7 2.365 1.895 8 2.306 1.860 9 2.262 1.833 A. Do not reject the null hypothesis. The data do not provide sufficient evidence that the average distance is greater than 160 yards. B. Reject the null hypothesis. The data does provide sufficient evidence that the average distance is greater than 160 yards. C. t= 1.2334; Critical value = 1.992 D. Insufficient information to answer this question. Question 25 of 40 2.5/ 2.5 Points A golfer wished to find a ball that would travel more than 180 yards when hit with his 5-iron with a club speed of 90 miles per hour. He had a golf equipment lab test a low compression ball by having a robot swing his club 7 times at the required speed. Data from this test resulted in a sample mean of 184.2 yards and a sample standard deviation of 5.8 yards. Assuming normality, carry out a hypothesis test at the 0.05 significance level to determine whether the ball meets the golfers requirements. Use the partial t-table below. Area in one tail 0.025 0.05 Area in two tails Degrees of Freedom n - 1 0.05 0.10 6 2.447 1.943 7 2.365 1.895 8 2.306 1.860 9 2.262 1.833 A. Reject the null hypothesis. The data do not provide sufficient evidence that the average distance is greater than 180 yards. B. Reject the null hypothesis. The data do provide sufficient evidence that the average distance is greater than 180 yards. C. Do not reject the null hypothesis. The data do provide sufficient evidence that the average distance is greater than 180 yards. D. Do not reject the null hypothesis. The data do not provide sufficient evidence that the average distance is greater than 180 yards. Question 26 of 40 2.5/ 2.5 Points One hundred people are selected at random and tested for colorblindness to determine whether gender and colorblindness are independent. The following counts were observed. Colorblind Not Colorblind Total Male 7 53 60 Female 1 39 40 Total 8 92 100 State the null and alternative hypothesis for the information above. A. H0: Colorblindness and gender are dependent characteristics. Ha: Colorblindness and gender are related in some way. B. H0: Colorblindness and gender are independent characteristics. Ha: Colorblindness and gender are not related in any way. C. H0: Colorblindness and gender are dependent characteristics. Ha: Colorblindness and gender are not related in any way. D. H0: Colorblindness and gender are independent characteristics. Ha: Colorblindness and gender are related in some way. Question 27 of 40 2.5/ 2.5 Points Which of the following statements is true? A. The p distribution cannot be used when finding a confidence interval for the population mean with a small sample anytime the population standard deviation is unknown. B. The t distribution can be used when finding a confidence interval for the population mean with a small sample anytime the population standard deviation is unknown. C. The t distribution cannot be used when finding a confidence interval for the population mean with a small sample anytime the population standard deviation is unknown. D. The p distribution can be used when finding a confidence interval for the population mean with a small sample anytime the population standard deviation is unknown. Question 28 of 40 2.5/ 2.5 Points One hundred people are selected at random and tested for colorblindness to determine whether gender and colorblindness are independent. The following counts were observed. Colorblind Not Colorblind Total Male 7 53 60 Female 1 39 40 Total 8 92 100 If gender and colorblindness are independent, find the expected values corresponding to the female combinations of gender and colorblindness. A. Colorblind Female 4.8; Not Colorblind Female 55.2 B. Colorblind Female 3.2; Not Colorblind Female 36.8 C. Colorblind Female 4.8; Not Colorblind Female 35.2 D. Colorblind Female 3.8; Not Colorblind Female 36.2 Question 29 of 40 0.0/ 2.5 Points A 95% confidence interval for the mean of a normal population is found to be 17.6 < < 23.6. What is the margin of error? A. 2.0 B. 2.7 C. 3.0 D. 4.0 Question 30 of 40 0.0/ 2.5 Points The following data were analyzed using one-way analysis of variance. A B C 34 27 19 26 23 21 31 29 22 28 21 12 Which one of the following statements is correct? A. The purpose of the analysis is to determine whether the groups A, B, and C are independent. B. The purpose of the analysis is to test the hypothesis that the population means of the three groups are equal. C. The purpose of the analysis is to test the hypothesis that the population variances of the three groups are equal. D. The purpose of the analysis is to test the hypothesis that the sample means of the three groups are equal. Question 31 of 40 0.0/ 2.5 Points One hundred people are selected at random and tested for colorblindness to determine whether gender and colorblindness are independent. The following counts were observed. Colorblind Not Colorblind Total Male 8 52 60 Female 2 38 40 Total 10 90 100 Find the value of the X2 statistic for the data above. A. 1.463 B. 1.852 C. 1.947 D. 1.949 Question 32 of 40 0.0/ 2.5 Points Which of the following statements is true? A. The t distribution can be used when finding a confidence interval for the population mean whenever the sample size is small. B. The p distribution can be used when finding a confidence interval for the population mean whenever the sample size is small. C. The t distribution cannot be used when finding a confidence interval for the population mean whenever the sample size is small. D. The p distribution cannot be used when finding a confidence interval for the sample mean whenever the sample size is small. Question 33 of 40 0.0/ 2.5 Points A simple random sample from a normal distribution is taken in order to obtain a 95% confidence interval for the population mean. If the sample size is 8, the sample mean x is 22, and the sample standard deviation s is 6.3, what is the margin of error? Show your answer to 2 decimal places. A. df = 7; E = 3.3445.38 = 5.6566 B. df = 8; E = 3.3445.38 = 5.6566 C. df = 6; E = 2.3656.38 = 5.769 D. df = 7; E = 2.3656.38 = 5.869 Question 34 of 40 0.0/ 2.5 Points The margin of error in estimating the population mean of a normal population is E = 9.3 when the sample size is 15. If the sample size had been 18 and the sample standard deviation did not change, would the margin of error be larger or smaller than 9.3? Explain your answer. A. Smaller. E decreases as the square root of the sample size gets larger. B. Smaller. E increases as the square root of the sample size gets larger. C. Larger. E decreases as the square root of the sample size gets larger. D. Larger. E increases as the square root of the sample size gets larger. Question 35 of 40 0.0/ 2.5 Points One hundred people are selected at random and tested for colorblindness to determine whether gender and colorblindness are independent. The critical value of X2 for a 2 x 2 table using a 0.05 significance level is 3.841. If the value of the X2 statistic is 4.613, state your conclusion about the relationship between gender and colorblindness. A. Reject H0. There is not sufficient evidence to support the claim that gender and colorblindness are related. B. Reject H0. There is sufficient evidence to support the claim that gender and colorblindness are related. C. Do not Reject H0. There is sufficient evidence to support the claim that gender and colorblindness are related. D. Do not Reject H0. There is not sufficient evidence to support the claim that gender and colorblindness are related. Question 36 of 40 0.0/ 2.5 Points A large test statistic F tells us that the sample means __________ the data within the individual samples, which would be unlikely if the populations means really were equal (as the null hypothesis claims). A. differ more than B. differ less than C. are equal to D. do not vary with Question 37 of 40 0.0/ 2.5 Points A 95% confidence interval for the mean of a normal population is found to be 15.6 < < 24.8. What is the margin of error? A. 4.4 B. 4.6 C. 4.8 D. 5.0 Question 38 of 40 0.0/ 2.5 Points One hundred people are selected at random and tested for colorblindness to determine whether gender and colorblindness are independent. The following counts were observed. Colorblind Not Colorblind Total Male 8 52 60 Female 2 38 40 Total 10 90 100 State the null and alternative hypothesis for the test associated with this data. A. H0: Colorblindness and gender are dependent characteristics. Ha: Colorblindness and gender are not related in any way. B. H0: Colorblindness and gender are dependent characteristics. Ha: Colorblindness and gender are related in some way. C. H0: Colorblindness and gender are independent characteristics. Ha: Colorblindness and gender are not related in any way. D. H0: Colorblindness and gender are independent characteristics. Ha: Colorblindness and gender are related in some way. Question 39 of 40 0.0/ 2.5 Points A 95% confidence interval for the mean of a normal population is found to be 15.6 < < 25.2. What is the margin of error? A. 3.9 B. 4.8 C. 4.9 D. 3.7 Question 40 of 40 2.5/ 2.5 Points One hundred people are selected at random and tested for colorblindness to determine whether gender and colorblindness are independent. The following counts were observed. Colorblind Not Colorblind Total Male 7 53 60 Female 1 39 40 Total 8 92 100 If gender and colorblindness are independent, find the expected values corresponding to the male combinations of gender and colorblindness. A. Colorblind Male 4.8; Not Colorblind Male 55.2 B. Colorblind Male 6.8; Not Colorblind Male 53.2 C. Colorblind Male 4.8; Not Colorblind Male 55.4 D. Colorblind Male 4.8; Not Colorblind Male 56.2