(a) In Exercise 3.7, how many of the 15 trucks would you expect to have blowouts?
(b) What is the variance of the number of blowouts experienced by the 15 trucks? What does that mean?

Exercise 3.7

In testing a certain kind of truck tire over rugged terrain, it is found that 25% of the trucks fail to complete the test run without a blowout. Of the next 15 trucks tested, find the probability that