Beginning inventory, purchases, and sales data for prepaid cell phones for May are as follows: Inventory Purchases Sales May 1 1,300 units at $36 May 10 650 units at $38 May 12 910 units May 20 585 units at $40 May 14 780 units May 31 390 units Assuming that the perpetual inventory system is used, costing by the LIFO method, determine the cost of merchandise sold for each sale and the inventory balance after each sale. Under LIFO, if units are in inventory at two different costs, enter the units with the HIGHER unit cost first in the Cost of Merchandise Sold Unit Cost column and LOWER unit cost first in the Inventory Unit Cost column.