Fairfield Automotive is the local dealership selling Honda automobiles. It recently stated in an advertisement that Honda owners average more than 85,000 miles before trading in or selling their Hondas. To test this, an independent agency selected a simple random sample of 80 Honda owners who have either traded or sold their Hondas and determined the number of miles on the car when the owner parted with the car. It plans to test Fairfield’s claim at the α = 0.05 level.
a. State the appropriate null and alternative hypotheses.
b. If the sample mean is 86,200 miles and the sample standard deviation is 12,000 miles, what conclusion should be reached about the claim?