Question: Consider a bank office where customers arrive according to a Poisson process with an average arrival rate of λ customers per minute. The bank has only one teller servicing the arriving customers. The service time is exponentially distributed and the mean service rate is µ customers per minute. It turns out that the customers are impatient and are only willing to wait in line for an exponential distributed time with a mean of 1/µ minutes. Assume that there is no limitation on the number of customers that can be in the bank at the same time.
a. Construct a rate diagram for the process and determine what type of queuing system this correspond to on the form A1/A2/A3.
b. Determine the expected number of customers in the system when λ = 1 and µ = 2.
c. Determine the average number of customers per time unit that leave the bank without being served by the teller when λ = 1 and µ = 2.