Can you please give me a detailed explanation on these questions ? I want to understand what I have been calculating wrong when I was trying. Much appreciated!

Eisen Hower, Inc. uses a periodic inventory system. The purchases of a particular product during the year are shown below: At December 31 the ending inventory consisted of 1,500 units. 8 31. Refer to the above data. Compute the cost of the ending inventory based on the LIFO method of inventory valuation. A. $12,500. B. $27,650. C. $10,975 D. $29,175. 32. Refer to the above data. Compute the cost of goods sold for the current year based on the LIFO method of inventory valuation. A. $12,500. B. $29,175. C. $10,975. D. $27,650 33. Refer to the above data. Compute the cost of the ending inventory based on the FIFO method of inventory valuation. A. $12,500. B. $29,175. C. $10,975. D. $27,650. 34. Refer to the above data. Compute the cost of goods sold for the current year based on the FIFO method of inventory valuation. A. $12,500. B. $29,175. C. $10,975. D. $27,650. 35. Refer to the above data. Compute the cost of the ending inventory based on the average-cost method of inventory valuation. (Rounded) A. $10,590. B. $11,700. C. $29,560. D. $28,450. 9 36. Refer to the above data. Compute the cost of goods sold for the current year based on the average- cost method of inventory valuation. A. $10,590. B. $11,700. C. $29,560. D. $28,450