MATH 302 QUIZ 5 – QUESTION AND ANSWERS – SET 2

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