Swifty Inc. uses a perpetual inventory system. Its records show the following for the month of May. Unit Cost $8 Date May 1 May 15 May 18 May 24 Explanation Inventory Purchase Sale Purchase Units 29 24 (45) 36 Total Cost $232 216 9 10 360 Total 44 $808 (a) Calculate the cost of goods sold for May and the ending inventory at May 31 using the FIFO formula. Cost of goods sold $ Ending Inventory $