The Environmental Protection Agency (EPA) publishes fuel economy values that are known to be good estimates of the fuel economy a typical driver will achieve under average driving conditions. Toyota Sienna, a popular minivan, advertises an average fuel usage of 22 mpg. A large rental company collected information about fuel economy (mpg) for their 10 Toyota Sienna minivans. The company calculates the sample mean to be 21.46 and sample standard deviation as 0.7367. The management believes that Toyota has overestimated the fuel economy of the Sienna. a) State the null and alternative hypotheses that should be used to determine whether the management's claim is correct.

b) What conditions must be met if we want to perform a hypothesis test to answer the management's question? You just need to list them. c) Assuming conditions for the hypothesis test are met, find the test statistic. d) Calculate the p-value and make your conclusion at the = 0.05 significance level.