The MIG/s/GD/s/ System (Blocked Customers Cleared) Example: An average of 20 ambulance calls per hour are received by Gotham City Hospital. An am- bulance requires an average of 20 minutes to pick up a patient and take the patient to the hospital. The ambulance is then available to pick up another patient. How many ambu- lances should the hospital have to ensure that there is at most a 1% probability of not be- ing able to respond immediately to an ambulance call? Assume that interarrival times are exponentially distributed