MATH 302 QUIZ 5 – QUESTION AND ANSWERS – SET 2 ( LATEST UPDATE )

MATH 302 QUIZ 5 – QUESTION AND ANSWERS – SET 2 Part 1 of 8 - 3.0/ 3.0 Points Question 1 of 17 1.0/ 1.0 Points A pharmaceutical company is testing the effectiveness of a new drug for lowering cholesterol. As part of this trial, they wish to determine whether there is a difference between the effectiveness for women and for men. Assume α = 0.05. What is the test value? Women Men Sample size 50 80 Mean effect 7 6.95 Sample variance 3 4 • A. z = 0.455 • B. t = 3.252 • C. z = 0.081 • D. t = 0.151 Answer Key:D 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 Which of the following statements is true regarding the F – distribution? • A. It is a distribution of negative values • B. It is always skewed to the left • C. It typically appears in tests of equal proportions • D. none of the above Answer Key:D Part 2 of 8 - 5.0/ 5.0 Points Question 4 of 17 1.0 / 1.0 Points In regression analysis, the variable we are trying to explain or predict is called the • A. regression variable • B. independent variable • C. dependent variable • D. residual variable Answer Key:C Question 5 of 17 1.0 / 1.0 Points The city of Oakdale wishes to see if there is a linear relationship between the temperature and the amount of electricity used (in kilowatts). Based on the data in the table below, is there a significant linear relationship between temperature and the amount of electricity used? These data are also available in the worksheet temperature in the Excel workbook T. T Temperature (x) 73 78 85 98 93 81 76 105 Kilowatts (y) 680 760 910 1510 1170 837 600 1800 • A. No, the sample correlation coefficient is equal to 0.981, which does not provide evidence of a significant linear relationship. • B. Yes, the sample correlation coefficient is equal to 0.878, which provides evidence of a significant linear relationship. • C. No, the sample correlation coefficient is equal to 0.098, which does not provide evidence of a significant linear relationship. • D. Yes, the sample correlation coefficient is equal to 0.981, which provides evidence of a significant linear relationship. Answer Key:D Question 6 of 17 1.0 / 1.0 Points Outliers are observations that • A. lie outside the typical pattern of points • B. disrupt the entire linear trend • C. lie outside the sample • D. render the study useless Answer Key:A Question 7 of 17 1.0 / 1.0 Points 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 1 2 3 4 5 6 Shelf Space 5 5 5 10 10 10 Weekly Sales 1.6 2.2 1.4 1.9 2.4 2.6 Store 7 8 9 10 11 12 Shelf Space 15 15 15 20 20 20 Weekly Sales 2.3 2.7 2.8 2.6 2.9 3.1 Is the correlation between weekly sales and shelf space significant at the .01 level of significance? • A. Yes, the p-value of the test for significance is less than .01. • B. Yes, the computed t-test statistic is less than the critical value. • C. No, the sample correlation coefficient does not exceed the critical value. • D. Yes, the value of the test statistic does not exceed the critical value. Answer Key:A Question 8 of 17 1.0/ 1.0 Points 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 1 2 3 4 5 6 Shelf Space 5 5 5 10 10 10 Weekly Sales 1.6 2.2 1.4 1.9 2.4 2.6 Store 7 8 9 10 11 12 Shelf Space 15 15 15 20 20 20 Weekly Sales 2.3 2.7 2.8 2.6 2.9 3.1 Compute the value of the sample correlation coefficient between weekly sales and shelf space. • A. 0.652 • B. 0.308 • C. 0.684 • D. 0.827 Answer Key:D Part 3 of 8 - 2.0/ 2.0 Points Question 9 of 17 2.0/ 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: 1.07 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 Part 4 of 8 - 2.0/ 2.0 Points Question 10 of 17 1.0/ 1.0 Points Click to see additional instructions Data for a sample of 25 apartments in a particular neighborhood are provided in the worksheet Apartments in the Excel workbook A. Using the estimated regression equation found by using size as the predictor variable, find a point estimate for the average monthly rent for apartments having 1,000 square feet of space. Place your answer, rounded to the nearest whole dollar, in the blank. 1242 When entering your answer do not use any labels or symbols. Simply provide the numerical value. For example, 123 would be a legitimate entry. A Answer Key:1237|1247 Question 11 of 17 1.0/ 1.0 Points Click to see additional instructions 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. Based on your results, If direct labor hours (DLH) increases by one hour, the indirect labor expense (ILE), on average, increases by approximately how much? Place your answer, rounded to 2 decimal places, in the blank. Do not use any stray punctuation marks or a dollar sign. For example, 34.56 would be a legitimate entry. 15.26 Answer Key:15.26 Part 5 of 8 - 2.0/ 2.0 Points Question 12 of 17 1.0/ 1.0 Points Click to see additional instructions 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/are the critical value you would use to conduct such a test of hypothesis? Place your answer, rounded to 2 decimal places, in the blank. If there are two critical values, place only the positive value in the blank. For example, 2.34 would be a legitimate entry. 1.64 Answer Key:1.64|1.65 Question 13 of 17 1.0/ 1.0 Points Click to see additional instructions 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 test value you would use to conduct such a test of hypothesis? Place your answer, rounded to 2 decimal places, in the blank. For example, 2.34 would be a legitimate entry. 1.16 Answer Key:1.15|1.16 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 testing the equality of two population variances, the test statistic is the ratio of the population variances; namely . True Fals e Answer Key:False Part 8 of 8 - 2.0/ 2.0 Points Question 16 of 17 1.0/ 1.0 Points 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 Answer Key:True Question 17 of 17 1.0/ 1.0 Points When the actual values y of a response variable and the corresponding predicted values y' are the same, the standard error of the estimate will be zero. True Fals e Answer Key:True