Beginning inventory, purchases, and sales for an inventory item are as follows: Sep. 1 Beginning Inventory 23 units @ $12 5 Sale 15 units 17 Purchase 25 units @ $15 30 Sale 19 units Assuming a perpetual inventory system and the last-in, first-out method: a. Determine the cost of the goods sold for the September 30 sale. b. Determine the inventory on September 30