Question: A random sample of 5 cars of type A that were test driven yielded the following gas mileage on the highway: 29.1, 29.6, 30, 30.5, 30.8. A random sample of 5 cars of type B yielded the following gas mileage when test driven under similar conditions: 21, 26, 30, 35, 38.
(a) For each type of car, estimate the population mean gas mileage.
(b) For each type of car, estimate the population variance of gas mileage.
(c) On the basis of the above analysis, rank the two types of car in terms of quality. Justify your answer.