Graczyk Company uses a periodic inventory system. During October, it sold 360 units of Product Z. Its beginning inventory and purchases during the month were as follows: Oct. 1 Beginning inventory 100 units @ $20 5 Purchases 100 units @ $24 10 Purchases 100 units @ $22 15 Purchases 100 units @ $24 20 Purchases 100 units @ $28 25 Purchases 100 units @ $26 Compute the cost of goods sold under each of three methods: (a) average-cost, (b) LIFO, and (c) FIFO. (Show your work.