I need help computing FIFO and LIFO

#4. Stratton Company's inventory records for the most recent years contain the following data: Beginning Inventory Purchases during year Quantity 7,000 18,000 25,000 Unit Cost $14.00 = 98,000 $16.00 = 288,000 15.44 386,000 Stratton Company sold a total of 20,500 units during the year. Requirement 1: Using the average-cost method, compute the cost of goods sold and ending inventory for the year Goods sold: 20,500 Closing inventory = 7,000 + 18,000 - 20,500 = 4,500 Average cost of inventory = 386,000/25,000 = 15.44 Average-Cost Method cost of goods sold = 20,500 x 15.44 = 316,520 Average-Cost Method ending inventory = 4,500 x 15.44 = 69,480 Requirement 2: Using the FIFO method, compute the cost of goods sold and ending inventory for the year. FIFO Method cost of goods sold = FIFO Method ending inventory = Requirement 3: Using the LIFO method, compute the cost of goods sold and the ending inventory for the year