The followings are inventory transactions of Coyotes Co. during May.

5/1 Beginning inventory of 300 units at $10/unit

5/5 Bought 1,000 units at $11/unit.

5/10 Sold 900 units for $15/unit.

5/15 Bought 1,200 units at $12/unit.

5/25 Sold 1,300 units for $15/unit.

Instructions: Compute costs of goods sold (COGS) and costs of ending inventory for May using the following methods under the perpetual inventory system. 1. Average method. 2. First In First Out method. 3. Last In First Out method.