Demand for devil's food whipped$-$cream layer cake at a local pastry shop can be approximated using a Poisson distribution with a mean of $7$ per day. The manager estimates it costs $$30$ to prepare each cake. Fresh cakes sell for $$33.$ Day$-$old cakes sell for $$30$ each. Use Table C$.$

a$-1.$ Assume one$-$half of the day$-$old cakes are sold, and the rest thrown out. What service level is achieved in this situation? $($Round your answer to $2$ decimal places.$)$

Service level

a$-2.$ What stocking level is appropriate to achieve this service level?

Stocking level