1. During the early morning hours, customers arrive at a branch post office at an average of 1.5 minutes per customer (Poisson), while clerks can handle transactions in an average time (exponential) of 3 minutes each. Please find the following: (Please keep five decimal points). a. The average time of customers waiting for service if three clerks are used (provide your answer in minutes). b. If four clerks are used, how much will customer waiting time be reduced in minutes)