A daily newspaper is stocked by a coffee shop so its patrons can purchase and read it while they drink coffee. The newspaper costs $$1\mathrm{.}16$ per unit and sells for $$1\mathrm{.}75$ 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

$=150$

and

$=30.$