Gavin Products uses a perpetual inventory system. For 2010 and 2011, Gavin has the following data:

Required:
1. For each year, compute cost of goods sold, the cost of ending inventory, and gross margin using FIFO.
2. For each year, compute cost of goods sold, the cost of ending inventory, and gross margin using LIFO.
3. For each year, compute cost of goods sold, the cost of ending inventory, and gross margin using the average cost method. (Note: Use four decimal places for per-unit calculations and round all other numbers to the nearest dollar.)
4. Which method would result in the lowest amount paid for taxes?
5. Which method produces the most realistic amount for income? For inventory? Explain your answer.
6. Compute Gavin€™s gross profit ratio and inventory turnover ratio under each of the three inventory costing methods. (Note: Round answers to two decimal places.) How would the choice of inventory costing method affect these ratios?

Purchase Price (per unit) Sale Price (per unit) Activity 2010 Beginning inventory Purchase 1, Feb. 15 Sale Mar. 10 Purchase 2, Sept. 15 Sale 2, Nov. 3 Purchase 3, Dec. 20 2011 Sale 3, Apr. 4 Purchase 4, June 25 Sale 4, Dec. 18 Units 9 200 300 320 500 550 150 $25 12 25 13 200 200 150 25 14 25