Perpetual Inventory Using FIFO Beginning inventory, purchases, and sales for Item ER27 are as follows: July 1 Inventory 61 units @ $19 9 Sale 44 units 13 Purchase 45 units @ $21 28 Sale 21 units Assuming a perpetual inventory system and using the first-in, first-out (FIFO) method, determine (a) the cost of merchandise sold on July 28 and (b) the inventory on July 31. a. Cost of merchandise sold on July 28 $ 441 X b. Inventory on July 31 882 X