(c) X Your answer is incorrect. Determine cost of goods sold during the period under a periodic inventory system using the average-cost method. (Round average-cost per unit to 3 decimal places, e.g. 12.502 and final answer to 0 decimal places, e.g. 1,250.) Average-cost Cost of goods sold during the period $ 69142 e Textbook and Media The accounting records of Sheffield Corp. show the following data. Beginning inventory 2,980 units at $5 Purchases 8,180 units at $6 Sales 9,050 units at $10