Repair calls are handled by one repairman at a photocopy shop. Repair time, including travel time, is exponentially distributed, with a mean of two hours per call. Requests for copier repairs come in at a mean rate of three per eight-hour day (assume Poisson). Determine the following: a. The average number of customers awaiting repairs. (Round your answer to 2 decimal places.) b. System utilization. c. The amount of time during an eight-hour day that the repairman is not out on a call d. The probability of two or more customers in the system. (Do not round intermediate calculations. Round your answer to 4 decimal places.)