Using a computerized Inventory Management System, a Paint Supply Store franchise continuously monitors the inventory of all the paint located at each of their $15$ stores and their distribution warehouse $.$ The Paint Supply Store franchise sells an average of $42$ gallons of Orange Paint every week $($for $52$ weeks per yearStandard Deviation of the Demand$=5$ gallons$).$ They purchase Orange Paint from their supplier at a price of $$2\mathrm{.}50$ per gallon It takes $1\mathrm{.}50$ weeks to receive an order from the supplier $.$ Administrative costs for Ordering paint have been estimated to be $$20$ per order. Holding Costs $=25\%$ of the purchase price per gallon per year. How much Safety Stock should the company hold to have a Service Level of $85\mathrm{.}0\%?$