E6-4 Elsa's Boards sells a snowboard, Xpert, that is popular with snowboard enthusiasts. Information relating to Elsa's purchases of Xpert snowboards during September is shown below. During the same month, 121 Xpert snowboards were sold. Elsa's uses a periodic inventory system. Sept. 1Inventory Sept. 12 Purchases Sept. 19Purchases Sept. 26Purchases DateExplanation Units Unit Cost Total Cost 26 45 20 50 $ 97 102 104 105 $ 2,522 4,590 2,080 5,250 $14,442 Totals 141 Instructions (a) Compute the ending inventory at September 30 and cost of goods sold using the FIFO and LIFO methods. Prove the amount allocated to cost of goods sold under each method. (b) For both FIFO and LIFO, calculate the sum of ending inventory and cost of goods sold. What do you notice about the answers you found for each method