11) An automobile manufacturer advertises that one of its models of cars achieves 28 miles per gallon for highway driving. A consumer advocacy group claims that the advertisement is incorrect and...

11) An automobile manufacturer advertises that one of its models of cars achieves 28 miles per gallon for highway driving. A consumer advocacy group claims that the advertisement is incorrect and selects a random sample of 32 nonprofessional drivers and each one drives the car from West Windsor, NJ to Washington, DC. The mean miles per gallon was determined to be 27.3 mpg with a standard deviation of 2.69. Assuming fuel efficiency is normally distributed under these circumstances, test the advocacy’s claim at  = 0.05. (Show all steps.)