QUESTION 1: Suppose the manufacturer claims that the mean lifetime of a tire is more than 11,000 kms. In a sample of 30 tires, it was found that they only last 10,000 kms on average. Assume the population standard deviation is 140 kms. At 0.05 significance level, can we reject the claim by the manufacturer? State the null and alternative hypotheses. Using the critical value approach, test the hypotheses. Let a = 0.05 Using the p-value approach, test the hypotheses at the 5% level of significance. what is your conclusion? a. b. C. d.