Problem $11-20($Algo$)$

Daily demand for a product is $100$ units, with a standard deviation of $15$ units. The review period is $20$ days and the lead time is $10$ days. At the time of review, there are $50$ units in stock.

If $98$ percent service probability is desired, how many units should be ordered?

Note: Use Excel's NORM.S$.$INV$()$ function to find the $z$ value. Round $z$ value to $2$ decimal places and final answer to the nearest whole number.

Ordered quantity

units