1.0 Points Question 1 of 17 Two independent samples of sizes n1 = 50 and n2 = 50 are randomly selected from two populations to test the difference between the population means, distribution of the sample mean difference, . The sampling is: A.chi-squared distributed with 99 degrees of freedom B.t - distributed with 98 degrees of freedom C.approximately normal D.normally distributed Reset Selection 1.0 Points Question 2 of 17 A field researcher is gathering data on the trunk diameters of mature pine and spruce trees in a certain area. The following are the results of his random sampling. Can he conclude, at the . 10 level of significance, that the average trunk diameter of a pine tree is greater than the average diameter of a spruce tree? Pine trees Spruce trees Sample size 40 70 Mean trunk diameter (cm) 45 39 100 150 Sample variance A. The data do not support the claim because the test value 1.29 is greater than 1.28. B.The data support the claim because the test value 2.78 is greater than 1.28. C.The data do not support the claim because the test value 1.29 is less than 1.64. D. The data support the claim because the test value 2.78 is greater than 1.64. Reset Selection Question 3 of 17 1.0 Points Serum ferritin is used in diagnosing iron deficiency. In a study conducted recently researchers discovered that in a sample of 28 elderly men the sample standard deviation of serum ferritin was 52.6 mg/L. For 26 younger men the sample standard deviation was 84.2 mg/L. At the .01 level of significance, do these data support the conclusion that the ferritin distribution in elderly men has a smaller variance than in younger men? A.Yes, because the test value 2.56 is greater than the critical value of 2.54 B.Yes, because the test value 2.56 is greater than the critical value 0.394 C.Yes, because the test value 0.390 is less than the critical value 2.54 D.No, because the test value 1.60 is less than the critical value of 2.54 Reset Selection Part 2 of 8 - Question 4 of 17 A correlation value of zero indicates. A.a strong linear relationship B.a weak linear relationship C.no linear relationship 1.0 Points D.a perfect linear relationship Reset Selection 1.0 Points Question 5 of 17 The marketing manager of a large supermarket chain would like to use shelf space to predict the sales of pet food. For a random sample of 12 similar stores, she gathered the following information regarding the shelf space, in feet, devoted to pet food and the weekly sales in hundreds of dollars. . Store Shelf Space Weekly Sales 1 5 1.6 2 5 2.2 3 5 1.4 4 10 1.9 5 10 2.4 6 10 2.6 Store Shelf Space Weekly Sales 7 15 2.3 8 15 2.7 9 15 2.8 10 20 2.6 11 20 2.9 12 20 3.1 Compute the value of the sample correlation coefficient between weekly sales and shelf space. A.0.684 B.0.827 C.0.652 D.0.308 Reset Selection 1.0 Points Question 6 of 17 The marketing manager of a large supermarket chain would like to use shelf space to predict the sales of pet food. For a random sample of 12 similar stores, she gathered the following information regarding the shelf space, in feet, devoted to pet food and the weekly sales in hundreds of dollars. . Store Shelf Space Weekly Sales 1 5 1.6 2 5 2.2 3 5 1.4 4 10 1.9 5 10 2.4 6 10 2.6 Store 7 8 9 10 Shelf Space 15 15 15 20 Weekly Sales 2.3 2.7 2.8 2.6 Is the correlation between weekly sales and shelf space significant at the 11 20 2.9 .01 level of 12 20 3.1 significance? A.No, the sample correlation coefficient does not exceed the critical value. B.Yes, the p-value of the test for significance is less than .01. C.Yes, the value of the test statistic does not exceed the critical value. D. Yes, the computed t-test statistic is less than the critical value. Reset Selection Question 7 of 17 Correlation is a summary measure that indicates: 1.0 Points A.the strength of the linear relationship between pairs of variables B.a curved relationship among the variables C.the magnitude of difference between two variables D.the rate of change in Y for a one unit change in X Reset Selection 1.0 Points Question 8 of 17 The regression line y' = -3 + 2.5 X has been fitted to the data points (28, 60), (20, 50), (10, 18), and (25, 55). The sum of the squared residuals will be: A.16.0 0 B.49.0 0 C.94.2 5 D.20.2 5 Reset Selection Part 3 of 8 2.0 Points Question 9 of 17 Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker. Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values. For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not. A field researcher is gathering data on the trunk diameters of mature pine and spruce trees in a certain area. The following are the results of his random sampling. Can he conclude, at the 0.10 level of significance, that the average trunk diameter of a pine tree is greater than the average diameter of a spruce tree? Pine trees Spruce trees Sample size 20 30 Mean trunk diameter (cm) 45 39 100 150 Sample variance What is the test value for this hypothesis test? Test value: Round your answer to three decimal places. What is the critical value? Critical value: Round your answer to three decimal places. Part 4 of 8 1.0 Points Question 10 of 17 Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker. Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values. For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not. The marketing manager of a large supermarket chain would like to determine the effect of shelf space (in feet) on the weekly sales of international food (in hundreds of dollars). A random sample of 12 equal -sized stores is selected, with the following results: Store 1 2 3 4 5 6 7 8 9 10 11 12 Shelf Space(X) Weekly Sales(Y) 10 2.0 10 2.6 10 1.8 15 2.3 15 2.8 15 3.0 20 2.7 20 3.1 20 3.2 25 3.0 25 3.3 25 3.5 Find the equation of the regression line for these data. What is the value of the coefficient of determination? Place your answer, rounded to 3 decimal places, in the blank. Do not use a dollar sign. For example, 0.345 would be a legitimate entry. 1.0 Points Question 11 of 17 Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker. Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values. For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not. A company has observed that there is a linear relationship between indirect labor expense (ILE) , in dollars, and direct labor hours (DLH). Data for direct labor hours and indirect labor expense for 18 months are given in the file ILE_and_DLH.xlsx Treating ILE as the response variable, use regression to fit a straight line to all 18 data points. What values for the intercept (a) and slope (b) do you obtain? Place your answers, rounded to 3 decimal places, in the blanks provided. Do not use any stray punctuation marks. For example, 34.567 would be a legitimate entry. intercept (a) = slope(b) = Part 5 of 8 1.0 Points Question 12 of 17 Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker. Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values. For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not. Two teams of workers assemble automobile engines at a manufacturing plant in Michigan. A random sample of 145 assemblies from team 1 shows 15 unacceptable assemblies. A similar random sample of 125 assemblies from team 2 shows 8 unacceptable assemblies. If you are interested in determining if there is sufficient evidence to conclude, at the 10% significance level, that the two teams differ with respect to their proportions of unacceptable assemblies, what is the p-value associated with such a test of hypothesis? Place your answer, rounded to 4 decimal places, in the blank. For example, .0123 would be a legitimate entry. 1.0 Points Question 13 of 17 Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker. Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values. For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not. Are America's top chief executive officers (CEOs) really worth all that money? One way to answer this question is to look at the annual company percentage increase in revenue versus the CEO's annual percentage salary increase in that same company. Suppose that a random sample of companies yielded the following data: percent change for corporation percent change for CEO 1 1 3 1 2 6 82 5 2 2 8 1 - 1 3 6 72 7 4 2 2 1 Do these data indicate that the population mean percentage increase in corporate revenue is greater than the population mean percentage increase in CEO salary? Use a 5% level of significance. What is the p-value associated with this test of hypothesis? Place your answer, rounded to 3 decimal places, in the blank. For example, 0.134 would be a legitimate entry. Part 6 of 8 - 3.0 Points Question 14 of 17 Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker. Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values. For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not. Researchers conducted an experiment to measure the effect of a drug on improving the quality of sleep as determined by how many more minutes of REM sleep were measured for each participant. One group of participants were given the experimental drug; the other (control) group was given a placebo. Does the evidence indicate that the drug improved the amount of REM sleep at a 0.01 level of significance? Answer each of the following parts. Experimental Control sample size mean sleep improvement sample variance group 35 group 50 12.8 9.1 56.3 61.2 What is the test value for this hypothesis test? Answer: Round your answer to two decimal places. What is the P-value for this hypothesis test? Answer: Round your answer to three decimal places. What is the conclusion of this hypothesis test? Choose one. 1. There is sufficient evidence to show that the experimental drug improved the quality of sleep. 2. There is not sufficient evidence to show that the experimental drug improved the quality of sleep. 3. There is sufficient evidence to show that the quality of sleep is different for the experimental drug than for the control drug. 4. There is not sufficient evidence to show that the control drug decreased the quality of sleep. Answer: Enter only a 1, 2, 3 or 4 for your answer. Part 7 of 8 1.0 Points Question 15 of 17 The number of degrees of freedom associated with the t-test, when the data are gathered from a paired samples experiment with 12 pairs, is 24. True Fals e Reset Selection Part 8 of 8 1.0 Points Question 16 of 17 A simple linear regression equation is given by y' = 5 + 3x. The predicted value of Y when X = 3 is 5. True Fals e Reset Selection 1.0 Points Question 17 of 17 A negative relationship between an explanatory variable X and a response variable Y means that as X increases, Y decreases, and vice versa. True Fals e 1.0 Points Question 1 of 17 Two independent samples of sizes n1 = 50 and n2 = 50 are randomly selected from two populations to test the difference between the population means, distribution of the sample mean difference, . The sampling is: A.chi-squared distributed with 99 degrees of freedom B.t - distributed with 98 degrees of freedom C.approximately normal D.normally distributed Reset Selection 1.0 Points Question 2 of 17 A field researcher is gathering data on the trunk diameters of mature pine and spruce trees in a certain area. The following are the results of his random sampling. Can he conclude, at the . 10 level of significance, that the average trunk diameter of a pine tree is greater than the average diameter of a spruce tree? Pine trees Spruce trees Sample size 40 70 Mean trunk diameter (cm) 45 39 100 150 Sample variance A. The data do not support the claim because the test value 1.29 is greater than 1.28. B.The data support the claim because the test value 2.78 is greater than 1.28. C.The data do not support the claim because the test value 1.29 is less than 1.64. D. The data support the claim because the test value 2.78 is greater than 1.64. Reset Selection Question 3 of 17 1.0 Points Serum ferritin is used in diagnosing iron deficiency. In a study conducted recently researchers discovered that in a sample of 28 elderly men the sample standard deviation of serum ferritin was 52.6 mg/L. For 26 younger men the sample standard deviation was 84.2 mg/L. At the .01 level of significance, do these data support the conclusion that the ferritin distribution in elderly men has a smaller variance than in younger men? A.Yes, because the test value 2.56 is greater than the critical value of 2.54 B.Yes, because the test value 2.56 is greater than the critical value 0.394 C.Yes, because the test value 0.390 is less than the critical value 2.54 D.No, because the test value 1.60 is less than the critical value of 2.54 Reset Selection Part 2 of 8 - Question 4 of 17 A correlation value of zero indicates. A.a strong linear relationship B.a weak linear relationship C.no linear relationship D.a perfect linear relationship Reset Selection 1.0 Points 1.0 Points Question 5 of 17 The marketing manager of a large supermarket chain would like to use shelf space to predict the sales of pet food. For a random sample of 12 similar stores, she gathered the following information regarding the shelf space, in feet, devoted to pet food and the weekly sales in hundreds of dollars. . Store Shelf Space Weekly Sales 1 5 1.6 2 5 2.2 3 5 1.4 4 10 1.9 5 10 2.4 6 10 2.6 Store Shelf Space Weekly Sales 7 15 2.3 8 15 2.7 9 15 2.8 10 20 2.6 11 20 2.9 12 20 3.1 Compute the value of the sample correlation coefficient between weekly sales and shelf space. A.0.68 4 B.0.82 7 C.0.65 2 D.0.30 8 Reset Selection 1.0 Points Question 6 of 17 The marketing manager of a large supermarket chain would like to use shelf space to predict the sales of pet food. For a random sample of 12 similar stores, she gathered the following information regarding the shelf space, in feet, devoted to pet food and the weekly sales in hundreds of dollars. . Store Shelf Space Weekly Sales Store 1 5 1.6 2 5 2.2 3 5 1.4 4 10 1.9 5 10 2.4 6 10 2.6 7 8 9 10 11 12 Shelf Space 15 15 15 20 20 Weekly Sales 2.3 2.7 2.8 2.6 2.9 Is the correlation between weekly sales and shelf space significant at the .01 level of 20 3.1 significance? A.No, the sample correlation coefficient does not exceed the critical value. B.Yes, the p-value of the test for significance is less than .01. C.Yes, the value of the test statistic does not exceed the critical value. D. Yes, the computed t-test statistic is less than the critical value. Reset Selection Question 7 of 17 Correlation is a summary measure that indicates: 1.0 Points A.the strength of the linear relationship between pairs of variables B.a curved relationship among the variables C.the magnitude of difference between two variables D.the rate of change in Y for a one unit change in X Reset Selection 1.0 Points Question 8 of 17 The regression line y' = -3 + 2.5 X has been fitted to the data points (28, 60), (20, 50), (10, 18), and (25, 55). The sum of the squared residuals will be: A.16. 00 B.49. 00 C.94. 25 D.20. 25 Reset Selection Part 3 of 8 2.0 Points Question 9 of 17 Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker. Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values. For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not. A field researcher is gathering data on the trunk diameters of mature pine and spruce trees in a certain area. The following are the results of his random sampling. Can he conclude, at the 0.10 level of significance, that the average trunk diameter of a pine tree is greater than the average diameter of a spruce tree? Pine trees Spruce trees Sample size 20 30 Mean trunk diameter (cm) 45 39 100 150 Sample variance What is the test value for this hypothesis test? Test value: Round your answer to three decimal places. 1.897 What is the critical value? Critical value: Round your answer to three decimal places. 1.299 Part 4 of 8 1.0 Points Question 10 of 17 Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker. Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values. For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not. The marketing manager of a large supermarket chain would like to determine the effect of shelf space (in feet) on the weekly sales of international food (in hundreds of dollars). A random sample of 12 equal -sized stores is selected, with the following results: Store 1 2 3 4 5 6 7 8 9 10 11 12 Shelf Space(X) Weekly Sales(Y) 10 2.0 10 2.6 10 1.8 15 2.3 15 2.8 15 3.0 20 2.7 20 3.1 20 3.2 25 3.0 25 3.3 25 3.5 Find the equation of the regression line for these data. What is the value of the coefficient of determination? Place your answer, rounded to 3 decimal places, in the blank. Do not use a dollar sign. For example, 0.345 would be a legitimate entry. 0.684 1.0 Points Question 11 of 17 Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker. Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values. For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not. A company has observed that there is a linear relationship between indirect labor expense (ILE) , in dollars, and direct labor hours (DLH). Data for direct labor hours and indirect labor expense for 18 months are given in the file ILE_and_DLH.xlsx Treating ILE as the response variable, use regression to fit a straight line to all 18 data points. What values for the intercept (a) and slope (b) do you obtain? Place your answers, rounded to 3 decimal places, in the blanks provided. Do not use any stray punctuation marks. For example, 34.567 would be a legitimate entry. intercept (a) = 15.15 slope(b) = 15.25 Part 5 of 8 1.0 Points Question 12 of 17 Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker. Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values. For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not. Two teams of workers assemble automobile engines at a manufacturing plant in Michigan. A random sample of 145 assemblies from team 1 shows 15 unacceptable assemblies. A similar random sample of 125 assemblies from team 2 shows 8 unacceptable assemblies. If you are interested in determining if there is sufficient evidence to conclude, at the 10% significance level, that the two teams differ with respect to their proportions of unacceptable assemblies, what is the p-value associated with such a test of hypothesis? Place your answer, rounded to 4 decimal places, in the blank. For example, .0123 would be a legitimate entry. 1.65 1.0 Points Question 13 of 17 Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker. Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values. For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not. Are America's top chief executive officers (CEOs) really worth all that money? One way to answer this question is to look at the annual company percentage increase in revenue versus the CEO's annual percentage salary increase in that same company. Suppose that a random sample of companies yielded the following data: percent change for corporation percent change for CEO 1 1 3 1 2 6 82 5 2 2 8 1 - 1 3 6 72 7 4 2 2 1 Do these data indicate that the population mean percentage increase in corporate revenue is greater than the population mean percentage increase in CEO salary? Use a 5% level of significance. What is the p-value associated with this test of hypothesis? Place your answer, rounded to 3 decimal places, in the blank. For example, 0.134 would be a legitimate entry. -1.761 Part 6 of 8 3.0 Points Question 14 of 17 Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker. Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values. For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not. Researchers conducted an experiment to measure the effect of a drug on improving the quality of sleep as determined by how many more minutes of REM sleep were measured for each participant. One group of participants were given the experimental drug; the other (control) group was given a placebo. Does the evidence indicate that the drug improved the amount of REM sleep at a 0.01 level of significance? Answer each of the following parts. Experimental Control sample size mean sleep group 35 improvement sample variance group 50 12.8 9.1 56.3 61.2 What is the test value for this hypothesis test? Answer: Round your answer to two decimal places. 2.20 What is the P-value for this hypothesis test? Answer: Round your answer to three decimal places. 0.015 What is the conclusion of this hypothesis test? Choose one. 1. There is sufficient evidence to show that the experimental drug improved the quality of sleep. 2. There is not sufficient evidence to show that the experimental drug improved the quality of sleep. 3. There is sufficient evidence to show that the quality of sleep is different for the experimental drug than for the control drug. 4. There is not sufficient evidence to show that the control drug decreased the quality of sleep. Answer: Enter only a 1, 2, 3 or 4 for your answer. 2.20,0.017, Part 7 of 8 1.0 Points Question 15 of 17 The number of degrees of freedom associated with the t-test, when the data are gathered from a paired samples experiment with 12 pairs, is 24. Tru e Fals e Reset Selection Part 8 of 8 1.0 Points Question 16 of 17 A simple linear regression equation is given by y' = 5 + 3x. The predicted value of Y when X = 3 is 5. Tru e Fals e Reset Selection 1.0 Points Question 17 of 17 A negative relationship between an explanatory variable X and a response variable Y means that as X increases, Y decreases, and vice versa. Tru e Fals e