A tire manufacturing company is reviewing its warranty for their rainmaker tire. The warranty is for 40,000 miles. The distribution of tire wear is normally distributed with a population standard deviation of 15,000 miles. The tire company believes that the tire actually lasts more than 40,000 miles. A sample of 49 tires revealed that the mean number of miles 45,000 miles. Test the hypothesis with a 0.05 significance level. that is our decision?
Use 5 step-procedure for testing a hypothesis.