The inventory records of Cushing Inc. reflected the following information for the year ended December 31, 2019: Number of Units Unit Cost Total Cost Inventory, January 1 200 $ 12.0 $ 2,400 Purchases: May 30 320 14.5 4,640 September 28 400 16.0 6,400 Goods available for sale 920 $ 13,440 Sales: April 10 (140 ) June 11 (300 ) November 1 (380 ) Inventory, December 31 100 Required: a. Assume that Cushing, Inc., uses a periodic inventory system. Calculate cost of goods sold and ending inventory under FIFO and LIFO. b. Assume that Cushing, Inc., uses a perpetual inventory system. Calculate cost of goods sold and ending inventory under FIFO and LIFO.