QUESTION $25$

$2\mathrm{.}5$ points

Suppose a call center has one agent answering the calls. Customers call in at the rate of $15$ per hour, and on average it takes $3$ minutes to answer a call. There is no limit on the queue length. The average time that a customer spends in the system is $12$ minutes. What is the average number of customers waiting in the system?

Cannot be determined

$4\mathrm{.}8$

$3$

$3\mathrm{.}6$

$2\mathrm{.}7$