Penalty per item short

A product has anormally distributeddemand of 240 units per month, a monthly holding cost of $0.25 per unit and a penalty per unit short of $5. Currently we are ordering this product through an (R,S) policy, R of 2 months and average order quantities of Q = 480.

What is the value of k that follows from a $5 per item short penalty?

For this value of k, what is the corresponding value of G(k)? Give your answer with four decimals.