A perishable dairy product is ordered daily at a particular supermarket. The product, which costs $$1\mathrm{.}2$ per unit, sells for $$1\mathrm{.}64$ per unit. If units are unsold at the end of the day, the supplier takes them back at a rebate of $$1$ per unit. Assume that daily demand is approximately normally distributed with $=145$ and $\backslash$sigma $=30.$