Inventory Costing Methods-Perpetual Method Chen Sales Corporation uses the perpetual inventory system. On January 1,2012, Chen had: 1,000 units of product A with a unit cost of $21 per unit. A summary of purchases and sales during 2012 follows: Unit Units Units Cost Purchased Sold Feb.2 Apr.6 $23 July 10 Aug.9 27 400 1,800 1,600 800 800 Dec.30 30 1,200 Required a. Assume that Chen uses the first-in, first-out method. Compute the cost of goods sold for 2012 and the ending inventory balance at December 31, 2012, for product A. b. Assume that Chen uses the last-in, first-out method. Compute the cost of goods sold for 2012 and the ending inventory balance at December 31, 2012, for product A. C. Assume that Chen uses the weighted-average cost method. Compute the cost of goods sold for 2012 and the ending inventory balance at December 31, 2012, for product A. Do not round until your final answers. Round to the nearest dollar. a. First-In, First-Out Ending Inventory 0 S 0 Cost of goods Sold b. Last-In, First-Out 0 Ending Inventory Cost of Goods Sold c. Weighted Average 0) Cost of Goods Sold 0