I dont know how to solve this, i need the answers.

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 50 units @ $100 Mar. 10 Purchase 60 units @ $112 Aug. 30 Purchase 20 units @ $120 Dec. 12 Purchase 70 units @ $122 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 First-in, first-out (FIFO) $ Last-in, first-out (LIFO) Weighted average cost