Please answer using inventory control with unknow demand and the QR policy

A small manufacturing facility stocks a single-use filter, part SUF100, for their production process. It costs the manufacturer $1.50 per filter to purchase and $100 per order placed. They use a holding cost of 28% annually. Monthly demand for SUF 100 follows a normal distribution with =280 and =77. The parts arrive five months after an order is placed. If a stockout occurs, the demand is backlogged, not lost, and costs the production facility $12.80 per part backordered. 1. Find the optimal order quantity and reorder level to minimize average annual cost of holding, setup, and stockout. 2. What is the average annual cost of holding, setup, and stockouts, when the Q,R-policy in part 1 is used