Question: Do problem 60, page 360. (3 points)

One of the major U.S. automakers wishes to review its warranty. The warranty covers the engine, transmission, and drivetrain of all new cars for us to two years or 24,000 miles, whichever comes first. The manufacture’s quality assurance department believes that the mean number of miles driven by owners is more than 24,000. A sample of 35 cars revealed that the mean number of miles was 24,421 with a standard deviation of 1,944 miles.

a. Conduct the following hypothesis test. Use the .05 significance level.

b. What is the largest value for the sample mean for which Ho is not rejected?

c. Suppose that population mean shifts to 25,000 miles. What is probability this change will not be detected?