16. (**) David Polston prints up T-shirts to be sold at local concerts. The T-shirts sell for $20, but only cost David

$6.50. However, because the T-shirts have concertspecific information on them, David can sell leftover shirts for only $3.00. Suppose the demand for shirts can be approximated with a normal distribution and the mean demand is 120 shirts with a standard deviation of 35. What is the target service level? How many shirts should David print up for a concert?