Sam$$s Pet Hotel operates $52$ weeks per year, $6$ days per week, and uses a continuous review inventory system.It purchases kitty litter for $$11\mathrm{.}70$ per bag. The follow$-$ing information is available about these bags. Demand $=90$ bags$/$week Order cost $=$ $$54/$order Annual holding cost $=27$ percent of cost Desired cycle@service level $=80$ percent Lead time $=3$ weeks $(18$ working days$)$ Standard deviation of weekly demand $=15$ bags Current on$-$hand inventory is $320$ bags, with no openorders or backorders.

Consider again the kitty litter ordering policy for Sam$$sPet Hotel in Problem $13.$

a$.$ Suppose that the weekly demand forecast of $90$ bags is incorrect and actual demand averages only $60$ bags per week. How much higher will total costs be$,$ owing to the distorted EOQ caused by this forecast error? Please show excel steps