A store stocks beer mugs and the demand for these beer mugs is 10,200 per year. It costs $120 per order of the mugs and it costs $1.35 per mug per year to keep the mugs in stock. Once an order is placed, it takes seven days to receive the order from the distributor. Determine the following:
a. Optimal order size
b. Minimum total annual inventory cost
c. Reorder point