The Environmental Protection Agency (EPA0 estimated that the 1994 Polaris automobile obtains a mean of 35 miles per gallon (mpg) on the highway. However, the company that manufactures the car claims that the EPA has underestimated the Polaris' mileage. To support its assertion, the company selects 50 1994 Polaris cars and records the mileage obtained for each car over a driving course similar to the one used by the EPA. From the sample, the mean was 38.2 mpg. Assume the population standard deviation is 7.1 mpg.
a. State the correct null and alternative hypotheses that the company wishes to test.
b. Calculate the test statistic that would be used for conducting the desired test.