Please do the T$-$shirts Problem with a sales price of $$16$ and production cost of $$12.$ Unsold shirts can be sold off at $$7.$ The demand is given by N$($mu $=59,$ sigma $=6).$

Part a: $3$ points

What is the under$-$stocking cost Cu$?$

Locally stored answer:

Part b: $3$ points

What is the over$-$stocking cost Co$?$

Locally stored answer:

Part c: $3$ points

What is the service level or critical fractile? $($Please state a probability with $4$ decimal places $($and not a percentage$).$

Locally stored answer:

Part d: $3$ points

What is the corresponding z$-$score?

Locally stored answer:

Part e: $3$ points

What is the optimal order quantity? Please round to a whole number.