please all question solved

Patients are treated by a single emergency unit in the emergency room of a hospital. Service time distribution is exponential with a mean of 1/4 = 1/6.2 hour per patient (i.e., = 6.2). Patients arrive according to a Poisson process with 1 = 3.8 patient per hour. Assume that steady-state has been reached. Q2-a). What is the expected number of patients in the emergency room? Q2-b) What is the expected number of patients waiting (in queue) for treatment? Q2-c) What is the average time that a patient spends in waiting (in queue) for treatment? Q2-d) What is the probability of more than two patients in the emergency room? Q2-e). The management thinks that the probability of one or more patients waiting (in queue) at any given time must be less than 0.04. What must be the minimum value of average number of patients served in an hour to satisfy this condition? Q2-f). What minimum level of service rate must be achieved to attain an average waiting time in the system (queue and service) that is one hour or less