I don't understand this and would like a step-by-step process on how this is solved by showing your work. Thank you

Aircard Corporation tracks the number of units purchased and sold throughout each accounting period but applies its inventory costing method at the end of each period as if it uses a periodic inventory system. The following are the transactions for the month of July. Unit Cost $ 35 July 1 July 5 July 13 July 17 July 25 July 27 39 Units 2,500 1,500 6,500 3,500 8,500 5,500 Beginning Inventory Sold Purchased Sold Purchased Sold 41 Calculate the cost of goods available for sale, ending inventory, and cost of goods sold if Aircard uses (a) FIFO, (b) LIFO, or (C) weighted average cost. (Round "Cost per Unit" to 2 decimal places.) FIFO LIFO Weighted Average Cost Cost of Goods Available for Sale Ending Inventory Cost of Goods Sold