Martinez Inc. uses a perpetual inventory system. Its records show the following for the month of May. Date Unit Cost $10 11 Total Cost $300 297 1 15 May May May May Explanation Inventory Purchase Sale Purchase Total Units 30 27 (46) 41 52 18 24 12 492 $1,089 (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 $ $