) Fuel Economy for Midsize Cars. The Department of Energy provides fuel economy ratings for all cars and light trucks sold in the United States. The Minitab Express file for this problem contains the estimated miles per gallon for city and highway driving for a sample of 40 cars classified as midsize in 2016. Use this data set to test the claim that midsize cars get more than 30 miles per gallon for highway driving at the 5% significance level.