Evaluate the waiting line properties of the following customer service operation. On the basis of past data, it has been estimated that customers arrive according to a Poisson process with an average interarrival time of 20 minutes. The time to service for a customer is exponentially distributed with a mean of 15 minutes.
A) What is the total time in the system for this service?
B) Determine the average number of people waiting for the service.
C) If the server worked an 8 hour day, how many hours on average, would the server be busy?
You can use excel to solve this problem.