Sheffield Inc. uses a perpetual inventory system. Its records show the following for the month of May. Date May 1 15 May 18 24 Unit Cost $8 9 Total Cost $224 234 Units 28 26 149) 39 May Explanation Inventory Purchase Sale Purchase Total May 10 390 $848 (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 5