13.8. Electronic Car-diogram (ECG), a firm specializing in the diagnosis of automo- bile engine problems, is planning to open a new service center with two diagnos- tic bays. Based on the experience at other ECG facilities, it has been found that the diagnostic service time is a uniform distribution between 40 and 60 minutes. Based on its historical experience and the demographics of the new location, ECG believes the average time between customer arrivals will be 60 minutes with a negative exponential distribution. Simulate eight hours (480 minutes) of opera- tions with a two-bay facility, recording the waiting time of customers. ECG ex- pects customers will wait while their cars are being diagnosed and plans to promote an unconditional guarantee that customers who wait more than 60 min- utes will receive a gift certificate. From your simulation, how many gift certifi- cates do you expect to give out per day?