March: Units Cost per Unit $80 90 Beginning inventory March 5 purchase March 10 sale March 20 purchase 20 40 45 15 100 a) Determine the ending inventory in units and total dollar value, assuming Gamma uses the periodic inventory system and the FIFO inventory costing method. b) Determine the cost of goods sold in dollar value, assuming Gamma uses the perpetual inventory system and the weighted average inventory costing method