unstreet's Department Store would like to develop an inventory ordering policy with a $98$ percent probability of not stocking out. To illustrate your recommended procedure, use as an example the ordering policy for white percale sheets.

Demand for white percale sheets is $3,900$ per year. The store is open $365$ days per year. Every three weeks $(21$ days$)$ inventory is counted and a new order is placed. It takes $15$ days for the sheets to be delivered. Standard deviation of demand for the sheets is four per day. There are currently $130$ sheets on hand.

How many sheets should you order? $($Use Excel's NORMSINV$()$ function to find the correct critical value for the given $\backslash$alpha $-$level. Do not round intermediate calculations. Round $"$z$"$ value to $2$ decimal places and final answer to the nearest whole number.$)$