A self-service store is being planned to open, and it is estimated that customers will arrive at a rate of one every 5 minutes based on an exponential distribution. The manager plans to install 3 cash registers that can serve each customer in 10 minutes according to an exponential distribution. a) Make the rate diagram for this model and find the steady-state probability distribution Find: b) The probability that a customer is waiting to be served c) The probability of having 2 or fewer customers waiting to be served d) The fraction of the day that the ATMs will be occupied e) How long will a client wait before being served?