Green land Company uses a perpetual inventory system. Selected transactions for the month of September are presented below. September 1 Opening Inventory showed 120 units at a cost of $8 each. 6 Purchased 150 units on credit at a cost of $9 each. 12 Purchased 180 units on credit at a cost of $10 each. 15 Purchased 200 units on credit at a cost of $11 each. 19 Sold 550 units to Magic Carpets, Inc for cash at a selling price of $30/unit. Requirements: a) What is the cost of goods sold and the ending inventory using the following methods: 1. FIFO 2. LIFO 3. AVCO b) briefly comment on your figures.