Time left $1$:$44$:$46$

For any one of the individual $s^{**}$ queues, what is the utilization of the server at the optimal staffing level $($optimal utilization$)?$

a$.0\mathrm{.}60$

b$.0\mathrm{.}80$

c$.0\mathrm{.}90$

d$.0\mathrm{.}75$

Clear my choice

Considering any one of the individual $s^{**}$ queues, derive the expected number of customers waiting in line.

a$.2\mathrm{.}25$ customers

b$.8\mathrm{.}1$ customers

c$.0\mathrm{.}9$ customers

d$.3\mathrm{.}2$ customers