Norris Company uses the perpetual inventory system and had the following purchases and sales during March.

Purchases Sales Units Unit Cost Units Selling Price/Unit 3/1 Beginning inventory 100 $40 3/3 Purchase 60 $50 3/4 Sales 70 $80 3/10 Purchase 200 $55 3/16 Sales 80 $90 3/19 Purchase 40 $60 3/25 Sales 120 $90