Please solve and show work

5. A police dispatch center receives, on average, 4 calls involving incidents that require a police visit per hour. A police unit can handle on average 2 incidents per hour. The cost of adding a police unit (C1) is $150 per hour and the estimated cost of waiting per incident (C2) is $600 per hour. Find: (a) given that currently there are 3 police units, what is the average waiting time before a police unit arrives for a reported incident (b) the optimum number of police units needed in order to minimize the expected total cost. 5. A police dispatch center receives, on average, 4 calls involving incidents that require a police visit per hour. A police unit can handle on average 2 incidents per hour. The cost of adding a police unit (C1) is $150 per hour and the estimated cost of waiting per incident (C2) is $600 per hour. Find: (a) given that currently there are 3 police units, what is the average waiting time before a police unit arrives for a reported incident (b) the optimum number of police units needed in order to minimize the expected total cost