Help with this Accounting 120 question about fifo and lifo please

Use the following information to complete this exercise: sales, 550 units for $12, 500; beginning inventory, 300 units; purchases, 400 units; ending inventory, 150 units; and operating expenses, $4,000. Complete the table for each situation. In Situations A and B (costs rising), assume the following: beginning inventory, 300 units at $12 = $3, 600; purchases, 400 units at $13 = $5, 200. In Situations C and D (costs falling), assume the opposite; that is, beginning inventory, 300 units at $13 = $3, 900; purchases, 400 units at $12 = $4, 800. Use periodic inventory procedures