A company that manufactures cars claims that the gas mileage for its new line of hybrid cars,
on the average, is 60 miles per gallon with a standard deviation of 4 miles per gallon. A random
sample of 16 cars yielded a mean of 57 miles per gallon. If the company’s claim is correct,
what is the probability that the sample mean is less than or equal to 57 miles per gallon?
Comment on the company’s claim about the mean gas mileage per gallon of its cars. What
assumptions did you make