Perpetual Inventory Using FIFO Beginning inventory, purchases, and sales for Item ER27 are as follows: August 1 Inventory 40 units @$17 9 Sale 33 units 13 Purchase 42 units@$20 28 Sale 16 units Assuming a perpetual inventory system and using the first-in, first-out (FIFO) method, determine (a) the cost of merchandise sold on August 28 and (b) the inventory on August 31. a. Cost of merchandise sold on August 28 b. Inventory on August 31