please answer this specific question using my numbers and show working

Problem 18-11 (Algo) One operator services a bank of five machines. Machine running time and service time are both exponential. Machines run for an average of 95 minutes between service requirements, and service time averages 30 minutes. The operator receives $20 per hour in salary and fringe benefits, and machine downtime costs $74 per hour per machine. Use Table 1. Table 2 and Table 3 a. If each machine produces 50 pieces per hour while running, find the average hourly output of each machine, when waiting and service times are taken into account. (Round your answer to 2 decimal places.) * Answer is complete but not entirely correct. Average hourly output 30.00 pieces b. Determine the optimum number of operators 2 operators 3 operators 4 operators