The pharmacy at Metropolitan Hospital receives $12$ requests for prescriptions each$$ hour, Poisson distributed. It takes the staff a mean time $4$ minutes to fill each following a negative exponential distribution.

Part $2$

$$a$)$ The number of units in the system is enter your response here prescriptions$($enter your response as a whole$$ number$).$

Part $3$

$$b$)$ The average time a prescription spends in the system is enter your response here minutes $($round your response to the nearest whole$$ number$).$

Part $4$

$$c$)$ The average number of prescriptions waiting in the system is enter your response here prescriptions $($round your response to one decimal$$ place$).$