chou sales corporation uses the perpetual inventory system. on january 1, chen had 1,000 units of product a with a unit cost of $20 per unit. a summary of purchases and sales during the year follows: unit cost units purchased units sold feb.2 400 apr.6 $22 1,800 july 10 1,600 aug.9 25 800 oct.23 800 dec.30 28 1,400 required a. assume that chou uses the first-in, first-out method. compute the cost of goods sold for the year and the ending inventory balance at december 31 for product a. b. assume that chou uses the last-in, first-out method. compute the cost of goods sold for the year and the ending inventory balance at december 31 for product a. c. assume that chou uses the weighted-average cost method. compute the cost of goods sold for the year and the ending inventory balance at december 31 for product a. do not round until your final answers. round to the nearest dollar. a. first-in, first-out ending inventory answer cost of goods sold answer b. last-in, first-out ending inventory answer cost of goods sold answer c. weighted average ending inventory answer cost of goods sold answer