Calculating amounts and ratios under FIFO and LIFO (LO 10-2, LO 10-4) Keefer, Inc., began business on January 1, 20X1. Information on its inventory purchases and sales during 20X1 and 20X2 follow: Inventorv Sales Required: 1. Calculate ending inventory, cost of goods sold, and gross margin for 20X1 and 20X2 under the periodic FIFO inventory valuation method. 2. Calculate ending inventory, cost of goods sold, and gross margin for 20X1 and 20X2 under the periodic LIFO inventory valuation method. 3. Discuss the difference in reported results under FIFO versus LIFO for each year