In January, inventory has the following changes: 1. Jan 1: Beginning balance is $20,000(1,000 units at a unit cost of $20) 2. Jan 4: Sold 700 units for $30/ unit 3. Jan 10: Purchased 500 units at a unit cost of $22.40 4. Jan 22: Sold 360 units for $30/ unit 5. Jan 28: Sold 240 units for $30 / unit 6. Jan 30: Purchased 600 units at a unit cost of $23.30 Question: Assuming a perpetual inventory system, calculate cost of goods sold and ending balance of inventory under: 1. FIFO costing method 2. LIFO costing method 3. AVCO costing method Journalize transactions under different costing methods