Question $9$

$0\mathrm{.}5pts$

Demand for a coffee cup is normally distributed with a mean of $18$ units per week and a standard deviation in weekly demand of $5$ units. The lead time is $2$ weeks, and the business operates $52$ weeks per year. The continuous review system called for an EOQ of $75$ units and a cycle$-$service level of $90$ percent $($for $90\%$ service level, assume the value of $z=1\mathrm{.}28).$ What is the time between reviews under periodic review system $(P$ system$)?$

$4\mathrm{.}2$ weeks

$6\mathrm{.}2$ weeks

$8\mathrm{.}2$ weeks

$2\mathrm{.}2$ weeks