A small grocery store buys one-gallon bottles of milk from a local dairy farmer. The store buys milk from the dairy farmer at a cost of $2.00 per gallon and sells it for $3.50 per gallon. The demand for milk is normally distributed with a mean of 30 one-gallon bottles per day and a daily standard deviation of 3 bottles. At the end of each business day, any unsold milk is purchased by local restaurants for $1.00 per bottle (in U.S. dollars):

1. Determine the service level.

2. What is the optimal stocking level for the service level determined in (a)?