A factory orders supplies every 5 days. The lead time for deliveries is 8 days. Demand for wax averages 15 pounds per day with a standard deviation of 1.8 pounds. The holding cost for wax is $0.57 per pound per day. The factory wants to achieve an in-stock probability rate of 99.99% for wax.

On average, how many pounds of wax will the factory have on order?

on-order inventory = _____