Perpetual Inventory Using FIFO Beginning inventory, purchases, and sales for Item Zeta 9 are as follows: Oct. 1 Inventory 7 Sale 57 units @ $18 47 units 61 units @ $21 17 units 15 Purchase 24 Sale 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. a. Cost of goods sold on October 24 $ 1,191 1,134 b. Inventory on October 31 $