Customers arrive at Valdez's Real Estate at an average rate of one per hour. Arrivals can be assumed to follow the Poisson distribution. Juan Valdez, the agent, estimates that he spends an average of 30 minutes with each customer. The standard deviation of service time is 15 minutes, and the service time distribution is arbitrary.
(a) Calculate the operating characteristics of the queuing system at Valdez's agency.
(b) What is the probability that an arriving customer will have to wait for service?