Perpetual Inventory Using FIFO Beginning inventory, purchases, and sales for Item Zeta9 are as follows: Oct. 1 Inventory 61 units $20 7 Sale 45 units 15 Purchase 54 units $23 24 Sale 21 units Assuming a perpetual inventory system and using the first-in, first-out (FIFO) method, determine (a) the cost of goods sold on October 24 and (b) the Inventory on October 31. 474 X a. Cost of goods sold on October 24 231 X b. Inventory on October 31