Shown below is activity for one of the products of Denver Office Equipment: January 1 balance, 500 units @ $55 per unit $27,500 Purchases: January 10: 500 units @ $60 per unit January 20: 1,000 units @ $63 per unit Sales: January 12: 800 units January 28: 750 units 1. Compute the January 31 ending inventory and cost of goods sold for January, assuming Denver uses FIFO. 2. Compute the January 31 ending inventory and cost of goods sold for January, assuming Denver uses average cost and a periodic inventory system. 3. Compute the January 31 ending inventory and cost of goods sold for January, assuming Denver uses average cost and a perpetual inventory system. 4. Compute the January 31 ending inventory and cost of goods sold for January, assuming Denver uses LIFO and a periodic inventory system