The US department of energy's fuel economy guide provides fuel efficiencydata for cars and trucks.the fuel efficiency rating for city driving in terms of miles per gallon for a random sample of 30 midsize cars and a random sample of 20 large cars provided the following data:
midsize:
21 18 21 22 24 19 20 26 19 19
19 24 20 23 18 21 19 28 20 23
21 23 20 21 18 21 24 19 21 24
large:
17 21 16 17 16 18 17 16 17 21
17 19 17 17 17 17 18 17 16 17
a) What is the point estimate of the difference between the mean fuel efficiency rating for midsize cars and large cars?
b) Formulate the hypothesis that can be used to determine whether the sample data support the hypothesis that the mean fuel efficiency rating for midsize cars is greater than the mean fuel efficiency for large cars.
c) Compute the p-value for the hypothesis test.
d) At α = .05, what is your conclusion?