Suppose that wait times for customers at a grocery store cashier line are uniformly distributed between one minutes and fifteen minutes.
(a) What are the mean and variance of the waiting time?
(b) What is the probability that a customer waits less than seven minutes?
(c) What is the probability that a customer waits between four and twenty minutes?
(d) Suppose that a customer who waits k minutes in line receives a coupon worth a 0.2 k^(1/4) dollar discount on a future visit. What is the mean of the coupon value for a customer?