Sheffield Corp. sells a snowboard, EZslide, that is popular with snowboard enthusiasts. Below is information relating to Sheffield Corp.'s purchases of EZslide snowboards during September. During the same month, 100 EZslide snowboards were sold. Sheffield Corp. uses a periodic inventory system. Date Explanation Units Unit Cost Total Cost Sept. 1 Inventory 10 $100 $1,000 Sept. 12 Purchases 45 103 4,635 Sept. 19 Purchases 50 104 5,200 Sept. 26 Purchases 20 20 105 2,100 Totals 125 $12,935 (a) Compute the ending inventory at September 30 using the FIFO, LIFO and average-cost methods. (Round average cost per unit to 3