Current Attempt in Progress Swifty Corporation uses a periodic inventory system. Its records show the following for the month of May, in which 72 units were sold. Date Explanation Units Unit Cost Total Cost May 1 Inventory 33 $10 $330 15 Purchases 28 13 364 24 Purchases 39 14 546 Totals 100 $1,240 Compute the ending inventory at May 31 and cost of goods sold using the FIFO, LIFO, and average-cost methods. (Round per unit cost to 3 decimal places, e.g. 15.647 and final answers to O decimal places, e.g. 5,125.) FIFO Ending inventory at May 31 $ Cost of goods sold $ LIFO Average-cost $ $