On average, how much time does a customer spend on hold in a single$-$server model? $($minutes$)$

Group of answer choices

$1\mathrm{.}95$

$3\mathrm{.}67$

$14\mathrm{.}5$

$8\mathrm{.}405$

$1\mathrm{.}06$

$12\mathrm{.}71$

$7\mathrm{.}75$