Pina Inc. uses a perpetual inventory system. Its records show the following for the month of May. Unit Total Date Explanation Units Cost Cost May 1 Inventory 29 $8 $232 May 15 Purchase 27 9 243 May 18 Sale (41) May 24 Purchase 38 10 380 Total 53 $855 (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 $