Waterway Co. uses a periodic inventory system. Its records show the following for the month of May, in which 76 units were sold. Unit Cost Units Total Cost $12 $396 May 1 15 24 Inventory Purchases Purchases Totals 33 26 39 390 624 $1,410 Compute the ending inventory at May 31 and cost of goods sold using the FIFO and LIFO methods. FIFO LIFO Ending Inventory at May 31 Cost of goods sold