continue using your findings in the previous questions to answer the following:

$($a$)$ Calculate the average number of customer waiting.

$($b$)$ Calculate the percent of time that the server is busy.

$($c$)$ Calculate the percent of time that the server is idle.

$($d$)$ Calculate the average time a customer spends in the system $($counting waiting time and service time$).$

$($e$)$ Calculate the average time a customer spends waiting.