Suppose that the miles per gallon rating of passenger cars is normally distributed random variable with a mean and a standard deviation of 38.9 and 3.1 mpg, respectively. Use table 1.
a. What is the probability that a random selected passenger car gets more than 40 mpg? Round z value to 2 decimal places and final answer to 4 places
b. What is the probability that the average mpg of three randomly selected passenger cars is more than 40 mpg
c. If three passenger cars are randomly selected what is the probability that all of the passenger cars get more than 40 mpg?