A tire company claims that the average mileage of a certain brand of tires can last is 29,200 miles. A sample of n = 22 tires is taken at random to assess their mileage, resulting in the sample mean x = 29, 132 and sample variance s = 2, 236. Assuming that the distribution is normal: (a) test the hypothesis that the true average mileage of the tires is different from 29,200 miles. Choose confidence level a = 0.01. (b) find a 99 percent confidence interval for