Answer to Question #2460 in Statistics and Probability for mudassar
Q1. A small bank has two cashiers dealing with customers wanting to withdraw or deposit cash. For each cashier, the time to deal with a customer is a random variable having a normal distribution with mean 150s and standard deviation 45s.
A. Find the probability that the time taken for a randomly chosen customer to be dealt with by a cashier is more than 180s.
B. One of the cashier deals with two customers, one straight after the other.
Let X be the time to deal with a customer. Then Z = (X-150)/45is a random variable which has standard normal.