Shamrock, inc. sells a snowboard, ezslide, that is popular with snowboard enthusiasts. below is information relating to shamrock, inc.'s purchases of ezslide snowboards during september. during the same month, 104 ezslide snowboards were sold. shamrock, inc. uses a periodic inventory system. explanation inventory purchases purchases purchases totals units 12 45 51 19 127 unit cost total cost date sept. 1 sept. 12 sept. 19 sept. 26 $95 98 1,140 4,410 5,049 1,900 $12,499 100 (a) compute the ending inventory at september 30 using the fifo, lifo and average-cost methods. (round average cost per unit to 3 decimal places, e. g. 125.153 and final answers to 0 decimal places, e. g. 125.) fifo lifo average-cost the ending inventory at september 30 (b) compute the cost of goods sold at september 30 using the fifo, lifo and average-cost methods. (round average cost per unit to 3 decimal places, e. g. 125.153 and final answers to 0 decimal places, e. g. 125.) fifo lifo average-cost cost of goods sold s