A random sample of the gas mileage achieved by 20 domestic compact automobiles resulted in the following outcome:

(25.52,24.90,22.24,22.36,26.62,23.46,25.46,24.98,25.82, 26.10,21.59,22.89,27.82,22.40,23.98,27.77,23.29,24.57, 23.97,24.70).

(a) Define and graph the empirical distribution function.

(b) What is the estimated probability that gas mileage will exceed 26 miles per gallon?

(c) What is the estimated probability that gas mileage will be between 24 and 26 miles per gallon?

(d) Acting as if the EDF is the true CDF of gas mileages, calculate the expected value of gas mileage. Is the value you calculated equal to the sample mean? Why or why not?