QUIZ 5 MATH 302 GRADED | 2022 questions & answers update | 100% correct

QUIZ 5 MATH 302 GRADED Part 1 of 8 - 3.0/ 3.0 Points Question 1 of 17 1.0/ 1.0 Points A researcher hypothesizes that the variation in the amount of money spent on business dinners is greater than the variation of the amount of money spent on lunches. The variance of nine business dinners was $6.12 and the variance of 12 business lunches was $0.87. What is the test value? • A. 49.50 • B. 9.61 • C. 7.03 • D. 3.10 Answer Key:C Question 2 of 17 1.0 / 1.0 Points Multiple myeloma or blood plasma cancer is characterized by increased blood vessel formulation in the bone marrow that is a prognostic factor in survival. One treatment approach used for multiple myeloma is stem cell transplantation with the patient’s own stem cells. The following data represent the bone marrow microvessel density for a sample of 7 patients who had a complete response to a stem cell transplant as measured by blood and urine tests. Two measurements were taken: the first immediately prior to the stem cell transplant, and the second at the time of the complete response. Patient 1 2 3 4 5 6 7 Before 158 189 202 353 416 426 441 After 284 214 101 227 290 176 290 At the .01 level of significance, is there sufficient evidence to conclude that the mean bone marrow microvessel density is higher before the stem cell transplant than after the stem cell transplant? • A. No • B. Yes • C. Cannot Determine Answer Key:A Question 3 of 17 1.0 / 1.0 Points 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. Is there sufficient evidence to conclude, at the 10% significance level, that the two teams differ with respect to their proportions of unacceptable assemblies? • A. No, since the test value does not exceed the critical value • B. No, since the p-value is less than 0.10 • C. Yes, since the p-value is greater than 0.10 • D. No, since the test value exceeds the critical value Answer Key:A Part 2 of 8 - 4.0/ 5.0 Points Question 4 of 17 1.0 / 1.0 Points The standard error of the estimate, sest, is essentially the • A. mean of the explanatory variable • B. mean of the residuals • C. standard deviation of the residuals • D. standard deviation of the explanatory variable Answer Key:C Question 5 of 17 1.0 / 1.0 Points In choosing the “best-fitting” line through a set of points in linear regression, we choose the one with the: • A. smallest sum of squared residuals • B. largest number of points on the line • C. largest sum of squared residuals • D. smallest number of outliers Answer Key:A Question 6 of 17 1.0 / 1.0 Points A correlation value of zero indicates. • A. a perfect linear relationship • B. a strong linear relationship • C. a weak linear relationship • D. no linear relationship Answer Key:D Question 7 of 17 1.0/ 1.0 Points In a simple linear regression analysis, the following sum of squares are produced: = 500 = 100 = 400 The proportion of the variation in Y that is explained by the variation in X is: • A. 80% • B. 20% • C. 25% • D. 50% Answer Key:A Question 8 of 17 0.0 / 1.0 Points A linear regression analysis produces the equation y = 5.32 + (-0.846)x Which of the following statements must be true? • A. As x increases, y increases, and the correlation coefficient must be positive. • B. As x increases, y increases, and the correlation coefficient must be negative. • C. As x increases, y decreases, and the correlation coefficient must be positive. • D. As x increases, y decreases, and the correlation coefficient must be negative. Answer Key:D Part 3 of 8 - 1.0/ 2.0 Points Question 9 of 17 1.0/ 2.0 Points Click to see additional instructions A survey of employees at a company finds that 32 of the 88 employees who drive to work were ever late during the past year, and 18 of the 64 employees who took public transportation were ever late during the past year. At α = 0.10, is there a difference between the proportion of employees who drove who were ever late and the proportion of employees who took public transportation who were ever late? Find the test value for the difference in the proportion of employees who were ever late for work in the past year. Answer: 2.78 Round your answer to two decimal places. What is your decision for this test? 1. The test value is greater than the critical value of 1.960. 2. The test value is less than the critical value of 1.645. 3. The test value is greater than the critical value of 1.282. 4. The test value is less than the critical value of 1.960. Answer: 2 Enter only a 1, 2, 3 or 4 for your answer. Answer Key:1.07, 2 Feedback:X1 = 32 n1 = 88 X2 = 18 n2 = 64 p-hat1 = 32/88 = 0. p-hat2 = 18/64 = 0.28125 p-bar = (32 + 18)/(88 + 64) = 0. q-bar = 1 - p-bar = 0. Using the formula on page 500, The critical value is found using Table F, bottom row, alpha = 0.10, two-tail test: 1.645. Part 4 of 8 - 1.0/ 2.0 Points Question 10 of 17 1.0/ 1.0 Points Click to see additional instructions 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 Shelf Space(X) Weekly Sales(Y) 1 10 2.0 2 10 2.6 3 10 1.8 4 15 2.3 5 15 2.8 6 15 3.0 7 20 2.7 8 20 3.1 9 20 3.2 10 25 3.0 11 25 3.3 12 25 3.5 Using the equation of the regression line for these data, predict the average weekly sales (in hundreds of dollars) of international food for stores with 13 feet of shelf space for international food. Place your answer, rounded to 3 decimal places , in the blank. Do not use a dollar sign. For example, 2.345 would be a legitimate entry. 2.442 Answer Key:2.442 Question 11 of 17 0.0/ 1.0 Points Click to see additional instructions 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 Shelf Space(X) Weekly Sales(Y) 1 10 2.0 2 10 2.6 3 10 1.8 4 15 2.3 5 15 2.8 6 15 3.0 7 20 2.7 8 20 3.1 9 20 3.2 10 25 3.0 11 25 3.3 12 25 3.5 Find the equation of the regression line for these data. What is the value of the standard error of the estimate? 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 Answer Key:0.308 Part 5 of 8 - 1.0/ 2.0 Points Question 12 of 17 0.0/ 1.0 Points Click to see additional instructions 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 15 6 12 3 12 28 6 8 7 2 2 percent change for CEO 17 -4 12 32 -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. 0.359 Answer Key:0.173 Question 13 of 17 1.0/ 1.0 Points Click to see additional instructions 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 15 6 12 3 12 28 6 8 7 2 percent change for CEO 17 -4 12 32 -1 2 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 critical value that you would use to conduct this test of hypothesis? Place your answer, rounded to 3 decimal places, in the blank. For example, 2.345 would be a legitimate entry. 1.895 Answer Key:1.895 Part 6 of 8 - 3.0/ 3.0 Points Question 14 of 17 3.0/ 3.0 Points Click to see additional instructions 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 group Control group sample size 35 50 mean sleep improvement 12.8 9.1 sample variance 56.3 61.2 What is the test value for this hypothesis test? Answer: 2.20 Round your answer to two decimal places. What is the P-value for this hypothesis test? Answer: 0.017 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: 2 Enter only a 1, 2, 3 or 4 for your answer. Answer Key:2.20, 0.017, 2 Part 7 of 8 - 1.0/ 1.0 Points Question 15 of 17 1.0/ 1.0 Points When the necessary conditions are met, a two-tail test is being conducted to test the difference between two population proportions. The two sample proportions are = 0.35 and = 0.42, and the standard error of the sampling distribution of is 0.054. The calculated value of the test statistic is 1.2963. True False Answer Key:False Part 8 of 8 - 2.0/ 2.0 Points Question 16 of 17 1.0/ 1.0 Points In every regression study there is a single variable that we are trying to explain or predict. This is called the response variable or dependent variable. True False Answer Key:True Question 17 of 17 1.0/ 1.0 Points If there is no linear relationship between two variables X and Y, the coefficient of determination, R2, must be 1.0. True False Answer Key:False