Retailers Warehouse $($RW$)$ is an independent supplier of household items to department stores. RW attempts to stock enough items for a $90$ percent service probability.

A stainless$-$steel knife set is one item it stocks. Demand $(1,800$ sets per year$)$ is relatively stable over the entire year. Whenever new stock is ordered, a buyer must ensure that numbers are correct for stock on$-$hand and then phone in a new order. The total cost involved to place an order is about $$5.$ RW figures that holding inventory in stock and paying for interest on borrowed capital, insurance, and so on$,$ add up to about $$3$ holding cost per unit per year.

Analysis of the past data shows that the standard deviation of demand from retailers is about four units per day for a $365-$day year. Lead time to get the order is seven days.

a$.$ What is the economic order quantity? $($Round your answer to the nearest whole number.$)$

b$.$ What is the reorder point? $($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.$)$