MATH 302 Quiz 5 PRACTICE EXAM QUESTIONS AND ASWERS 2021

MATH 302 Quiz 5 PRACTICE EXAM QUESTIONS AND ASWERS 2021 Question 1 of 17 1.0/ 1.0 Points Q-Mart is interested in comparing its male and female customers. Q-Mart would like to know if the amount of money spent by its female charge customers differs, on average, from the amount spent by its male charge customers.  To answer this question, an analyst collected random samples of 25 female customers and 22 male customers. Based on these samples, on average, the 25 women charge customers spent $102.23 and the 22 men charge customers spent $86.46. Moreover, the sample standard deviation of the amount charged by the 25 women was $93.393, and the sample standard deviation of the amount charged by the 22 men was $59.695.  Using the procedure advocated by Bluman,  at the 10% level of significance, is there sufficient evidence for Q-Mart to conclude that, on average, the amount spent by women charge customers differs from the amount spent by men charge customers.  A.Yes, the p-value of this test is greater than 0.10  B.No, the p-value of this test is less than 0.10.  C.No, the test value does not exceed the critical value.  D.Yes, the test value does not exceed the critical value Question 2 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 test value exceeds the critical value  C.No, since the p-value is less than 0.10  D.Yes, since the p-value is greater than 0.10 Question 3 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 Part 2 of 8 - 5.0/ 5.0 Points Question 4 of 17 1.0/ 1.0 Points A correlation value of zero indicates.  A.a weak linear relationship  B.a strong linear relationship  C.a perfect linear relationship  D.no linear relationship Question 5 of 17 1.0/ 1.0 Points Outliers are observations that  A.lie outside the sample  B.lie outside the typical pattern of points  C.render the study useless  D.disrupt the entire linear trend Question 6 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.Yes, the sample correlation coefficient is equal to 0.878, which provides evidence of a significant linear relationship.  B.No, the sample correlation coefficient is equal to 0.981, which does not provide 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. Question 7 of 17 1.0/ 1.0 Points The standard error of the estimate, sest, is essentially the  A.mean of the residuals  B.mean of the explanatory variable  C.standard deviation of the explanatory variable  D.standard deviation of the residuals Question 8 of 17 1.0/ 1.0 Points In a simple linear regression analysis, the following sum of squares are produced:  = 400 = 80 = 320 The proportion of the variation in Y that is explained by the variation in X is:  A.50%  B.80%  C.20%  D.25% Part 3 of 8 - 2.0/ 2.0 Points Question 9 of 17 2.0/ 2.0 Points 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 30 35 Mean trunk diameter (cm) 45 39 Sample variance 120 140 What is the test value for this hypothesis test? What is the critical value? . Part 4 of 8 - 2.0/ 2.0 Points Question 10 of 17 1.0/ 1.0 Points 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 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 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   Question 11 of 17 1.0/ 1.0 Points 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 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   Part 5 of 8 - 1.0/ 2.0 Points Question 12 of 17 1.0/ 1.0 Points 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.  An investor wants to compare the risks associated with two different stocks. One way to measure the risk of a given stock is to measure the variation in the stock’s daily price changes.  In an effort to test the claim that the variance in the daily stock price changes for stock 1 is different from the variance in the daily stock price changes for stock 2, the investor obtains a random sample of 21 daily price changes for stock 1 and 21 daily price changes for stock 2.  The summary statistics associated with these samples are: n1 = 21, s1 = .848, n2 = 21, s2 = .529.  If you follow Bluman's advice and place the larger variance in the numerator when computing the test value, at the .05 level of significance, what is the critical value associated with this test of hypothesis? Place your answer, rounded to 2 decimal places, in the blank. For example, 3.45 would be a legitimate entry.  Question 13 of 17 0.0/ 1.0 Points 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.  Q-Mart is interested in comparing its male and female customers. Q-Mart would like to know if the amount of money spent by its female charge customers differs, on average, from the amount spent by its male charge customers. To answer this question, an analyst collected random samples of 25 female customers and 22 male customers.  Based on these samples, on average, the 25 women charge customers spent $102.23 and the 22 men charge customers spent $86.46. Moreover, the sample standard deviation of the amount charged by the 25 women was $93.393, and the sample standard deviation of the amount charged by the 22 men was $59.695.  Suppose, using a 10% level of significance, you wish to know if there is sufficient evidence for Q-Mart to conclude that, on average, the amount spent by women charge customers differs from the amount spent by men charge customers. That is suppose you wish to test  H0:    versus  H1:  Assuming that the amounts spent by male and female charge customers at Q-Mart are normally distributed, based on the procedure advocated by Bluman, what is the test value that you would use to conduct this test of hypothesis? Place your answer, rounded to 3 decimal places, in the blank. For example, 0.123 would be a legitimate entry Part 6 of 8 - 3.0/ 3.0 Points Question 14 of 17 3.0/ 3.0 Points 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 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? What is the P-value for this hypothesis test? 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. Part 7 of 8 - 1.0/ 1.0 Points Question 15 of 17 1.0/ 1.0 Points 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  False Part 8 of 8 - 2.0/ 2.0 Points Question 16 of 17 1.0/ 1.0 Points To help explain or predict the response variable in every regression study, we use one or more explanatory variables. These variables are also called predictor variables or independent variables.  True  False Question 17 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  False