It costs T $8 to make a specialty T-shirt. She produces T-shirts that are primarily sold at sporting events. She is trying to decide how many to produce for an upcoming event. During the event, T can sell T-shirts for $20 each. However, when the event ends, any unsold T-shirts are sold for $4 a piece. T's estimate of demand is the following:

300 0.05

400 0.10

500 0.40

600 0.30

700 0.10

800 0.05

a.What is the service rate (or optimal fractile)?

b.How many shirts should she produce for the upcoming event?