A supermarket has 4 cashiers. Customers have exponentially distributed interarrival times with the rate of 30 customers per hour. Assume that there is one waiting line and steady-state condition holds. The service time of each cashier is exponentially distributed with the mean of 6 minutes.
Construct the rate diagram for this queuing system.
What is the expected number of customers in the queuing system?
How long should an arriving customer expect to wait for service?
What is the expected number of customers waiting for service?