a. Assuming that the perpetual inventory system is used, costing by the LIFO method, determine the cost of goods sold for each sale and the inventory balance after each sale, presenting the data in the form illustrated in Exhibit 4. Under LIFO, if units are in inventory at two different costs, enter the units with the HIGHER unit cost first in the Cost of Goods Sold Unit Cost column and LOWER unit cost first in the Inventory Unit Cost column. Schedule of Cost of Goods Sold LIFO Method Prepaid Cell Phones Quantity Purchased Purchases Purchases Unit Cost Total Cost Quantity Sold Cost of Cost of Goods Sold Goods Sold Unit Cost Total Cost Date Inventory Quantity Inventory Unit Cost Inventory Total Cost Dec. 1 1,500 28 42,000 Dec. 10 750 30 22,500 1,500 V 28 42,000 750 30 22,500 Dec. 12 750 30 22,500 1,200 X X Dec. 14 900 300 Dec. 20 675 32 21,600 300 675 32 00 > 21,600 Dec. 31 450 32 14,400 300 225 32 7,200 Dec. 31 Balances