Problem: A factory orders supplies every 9 days. The lead time for deliveries is 4 days. Demand for copper averages 19 pounds per day with a standard deviation of 2.2 pounds. The holding cost for copper is $0.41 per pound per day. The restaurant wants to achieve an in-stock probability rate of 90% for copper.
On average, how many pounds of copper will the factory have on hand?
Note: Round your answer to 1 decimal place.