QUESTION $32$

Weekly demand for a particular item averages $30$ units, with a standard deviation of $4.$ This item is managed with a fixed$-$order$-$interval model. The order interval is three weeks, and this item has a certain lead time of one week. The desired service level is $97\mathrm{.}5$ percent. Assume that it is now time to place another order, and there are $43$ units on hand. How many units should be ordered?

$46$

$120$

$136$

$84$

$93$