Using the periodic inventory system, calculate the ending inventory and the Cost of Goods Sold under each of the following methods. Beginning Inventory 10 units @ $1 = $ 10 Purchases 20 units @ $2 = $ 40 30 units @ $3 = $ 90 40 units @ $4 = $160 100 units $300 Ending Inventory 20 units A) FIFO Periodic B) LIFO Periodic C) Weighted Average