Exercise 5 The management engineer has concluded that the arrivals of emergency cases can be modeled as a Poisson process with the average arrival rate per hour, =2. Further investigation tells that treating patient consists of 2 steps. A nurse interviews the patient and fills the questionnaire in the first step. The average time for this process is 10 minutes. Right after the initial interview, a doctor treats the patient. The average time for treatment is 10 minutes as well. Only one doctor and one nurse work in the emergency room. Both of the service times follow exponential distributions. Since there is only one bed for treating patient, either of the nurse and the doctor can treat a patient