Patients for the medical office of a very large plant arrive at an average of four per hour. Only one doctor is present and currently patients are processed at a rate of one in every 12 minutes.

a) What is the average number of patients waiting to be seen by the doctor?

b) How long will a patient spend on the average in the medical facility before they can return back to work or leave for the day if it is necessary?

c) The manager is considering hiring a second doctor so that his employees would not be gone so long as to shut down the production line, which can be very costly. In this case the patients who arrive would then wait for the first available doctor to be seen. If the second doctor works at the same rate, how long will a patient spend on the average in the medical facility before they can return back to work or leave for the day if it is necessary?