Demand for devil$$s food whipped$-$cream layer cake at a local pastry shop can be approximated using a Poisson distribution with a mean of $3\mathrm{.}4$ per day. The manager estimates it costs $$12$ to prepare each cake. Fresh cakes sell for $$15.$ Day$-$old cakes sell for $$12$ 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?

Note: Round your answer to $2$ decimal places.