When 200 randomly selected car owners are surveyed, it is found that the mean length of

time they plan to keep their car is 7.01 years, and the standard deviation is 3.47 years.

Calculate the appropriate test statistic to test the claim that the mean for all car owners is less

than 7.5 years.

A. -2.53

B. -1.997

C. -13.10

D. 1.31

Let p1 represent the population proportion of U.S. Senate and Congress (House of Representatives) democrats who are in favor of a new modest tax on "junk food". Let p2 represent the population proportion of U.S. Senate and Congress (House of Representative) republicans who are in favor of a new modest tax on "junk food". Out of the 265 democratic senators and congressman 106 of them are in favor of a "junk food" tax. Out of the 275 republican senators and congressman only 57 of them are in favor of a "junk food" tax. Find a 95 percent confidence interval for the difference between proportions l and 2.

A. (0.197 0.203)

B. (0.125 0.275)

C. (0.117 0.269)

D. (0.136 0.250)

We are interested in testing the following hypotheses. H0: 1- 2 0 Ha: 1- 2 > 0 The test statistic Z is computed to be 0.85. The p-value for this test is

A. 0.7190

B. 0.3803

C. 0.2810

D. 0.1977