Petromax Enterprises uses a continuous review inventory control system for one of its SKUs. The following information is available on the item. The firm operates $50$ weeks in a year. Refer to the standard normal table for z$-$values.

$>$ Demand $=50,000$ units$/$year

$>$ Ordering cost $=$$$\frac{35}{?}$ order

$>$ Holding cost $=$$$\frac{2}{?}$ unit$/$year

$>$ Average lead time $=3$ weeks

$>$ Standard deviation of weekly demand $=125$ units

a$.$ The economic order quantity for this item is $$ units. $($Enter your response rounded to the nearest whole number.$)$

b$.$ If Petromax wants to provide a $90\%$ service level, the safety stock is $$ units $($enter your response rounded to the nearest whole number$)$