Perpetual Inventory Using FIFO Beginning inventory, purchases, and sales for Item ER27 are as follows: May 1 Inventory 58 units @ $16 9 Sale 40 units 13 Purchase 60 units @ $17 28 Sale 22 units Assuming a perpetual inventory system and using the first-in, first-out (FIFO) method, determine (a) the cost of merchandise sold on May 28 and (b) the inventory on May 31. a. Cost of merchandise sold on May 28 $ b. Inventory on May 31 $