Using the gross requirements schedule in Examples 4, 5, and 6 in the text, prepare an alternative

Question:

Using the gross requirements schedule in Examples 4, 5, and 6 in the text, prepare an alternative ordering system that orders every 3 weeks for 3 weeks ahead (a periodic order quantity). Use the same costs as in the example (setup at $100 each, holding at $1 per unit per period). What is the cost of this ordering system?