1) 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
2) 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.
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.
3) 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.
4) 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 female and male charge customers at Q-Mart are normally distributed, based on the procedure advocated by Bluman, what is/are the critical values that you would use to conduct this test of hypothesis? Place your answer, rounded to 3 decimal places, in the blank. If there are two critical values, place only the positive value in the blank. For example, 2.035 would be a legitimate entry.
5) 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 12 3 12 28 6 8 2
percent change for CEO 6 17 -4 12 32 -1 7 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.