Choco Inc. uses a perpetual inventory system. If Choco Inc. uses the FIFO method, how much is the cost of goods sold (COGS) for September?

9/1 Beginning inventory 300units @ $5.4

9/5 Sales (price $10/unit) 150units

9/15 Purchase 500units @ $8.7

9/22 Sales (price $10/unit) 400units