David Polston prints up​ T-shirts to be sold at local concerts. The​ T-shirts sell for ​$23.30 each but cost David only ​$15.30 each.​ However, because the​ T-shirts have​ concert-specific information on​ them, David can sell a leftover shirt for only ​$8.70. Suppose the demand for shirts can be approximated with a normal distribution and the mean demand is 310 ​shirts, with a standard deviation of 90. Required:
What is the target service level?

Wo firms, a and b, each currently dump 50 tons of chemicals into the local river. the government has decided to reduce the pollution and from now on will require a pollution permit for each ton of pollution dumped into the river. it costs firm a $100 for each ton of pollution that it eliminates before it reaches the river, and it costs firm b $50 for each ton of pollution that it eliminates before it reaches the river. the government gives each firm 20 pollution permits. government officials are not sure whether to allow the firms to buy or sell the pollution permits to each other. what is the total cost of reducing pollution if firms are not allowed to buy and sell pollution permits from each other? what is the total cost of reducing pollution if the firms are allowed to buy and sell permits from each other? a. $3,000; $1,500 b. $4,500; $3,500 c. $4,500; $4,000 d. $4,500; $2,500