I can't figure out how I got these wrongs, please help explain

Cheyenne sells a snowboard, EZslide, that is popular with snowboard enthusiasts. The following is information relating to Cheyenne's beginning inventory and purchases of EZslide snowboards during September. During the same month, 104 EZslide snowboards were sold. Cheyenne uses a periodic inventory system. Compute the ending inventory at September 30 and the cost of goods sold using the FIFO, LIFO, and average-cost methods. (Round per unit cost to 3 decimal places, e.g. 15.647 and final answers to 0 decimal places, e.g. 5,125.)