The following information was available from the inventory of Key Company for January: Units Unit Cost 3,000 $9.77 Balance at Jan 1 Purchases: Jan 6 Jan 26 Sales: Jan 7 Jan 31 2,000 2,700 (2,500) (4,200) 10.30 10.71 Required: a. Assuming that the Perpetual Inventory system is used, what should be the COGS and ending inventory at January 31" using the moving average inventory method? b. Assuming that the Periodic Inventory system is used, what should be the COGS and ending inventory at January 31st using the weighted average method?