Question

Answer number 2 please.

1.         Records of 40 used passenger cars and 40 used pickup trucks were randomly selected to investigate the difference            in how long the owners kept their vehicles. For cars, the mean was 5.3 years with standard deviation 2.2 years.            For pickup trucks, the mean was 7.1 years with standard deviation 3.0 years. Find a 95% confidence interval for           the true difference in means. Add a sentence. (Note that these are all sample results.) (5)

2.         Using the information in Problem One, test the claim that customers keep trucks no longer than cars. Assume that the standard deviations above were population standard deviations.

            a. State the Null and the Alternative Hypotheses, explaining which is is which

            b. Show the Test Statistics and the standardized test statistic (4)

            c. State the conclusion about the claim and how you made the decision. (4)

Answer 1