E6-4 Mather sells a snowboard, EZslide, that is popular with snowboard enthusiasts. Below is information during September. During the same month, 102 EZslide snowboards were sold. Mather uses a periodic inventory system Date Explanation Umits Unit Cost Total Cost Sept 1 Inventory 12 $100 1,200 Sept. 12 Purchases 45 103 4,635 Sept. 19 Purchases 50 104 5,200 Sept. 26 Purchases 20 105 2,100 Totals 127 $13135 Instructions the ending inventory at September 30 and the cost of goods sold using the FIFO, LIFO, and average cost methods (For average-cost round the average unit cost to three decimal places) Prove the amount allocated to cost of goods sold under each method