A Tire Manufacturer Wishes to Compare Two Designs for Fiberglass

Short Answer

A tire manufacturer wishes to compare two designs for fiberglass belted tires with regard to tread wear. One tire of each design is placed on the rear wheels of each of seven test automobiles that are inspected regularly. The elapsed mileage until replacement is necessary is recorded for each tire. The following are the results (to the nearest 1000 miles):
Set up the statistical hypotheses; perform the test (α = .05) and draw final conclusions.