. The EPA uses a tailpipe test to determine if cars generate too much pollution. It is estimated that 1% of cars fail such a test. Twenty cars are randomly selected.

a. Find the mean and standard deviation for the number of cars in groups of 20 that fail the tailpipe test. Is it unusual to have 3 that fail the tailpipe test? Why or why not?

b. Find the probability that in a randomly selected group of 20 cars, exactly 1 car fails

c. Find the probability that in a randomly selected group of 20 cars, at least 2 cars fail.