periodic inventory by three methods; cost of merch sold. please help me

Periodic Inventory by Three Methods; Cost of Merchandise Sold The units of an item available for sale during the year were as follows: Jan. 1 Inventory 40 units @ $110 Mar. 10 Purchase 60 units @ $122 Aug. 30 Purchase 30 units @ $128 Dec. 12 Purchase 70 units @ $134 There are 80 units of the item in the physical inventory at December 31. The periodic inventory system is used. Determine the inventory cost and the cost of merchandise sold by three methods. Round interim calculations to one decimal and final answers to the nearest whole dollar. Cost of Merchandise Inventory and Cost of Merchandise Sold Inventory Method Merchandise Inventory Merchandise Sold Merchandise Inventory First-in, first-out (FIFO) $ 4,240 $ 20,700 X 15,560 9,380 Last-in, first-out (LIFO) 16,211 8,729 Weighted average cost