The following information relates to Glassworks Ltd.'s inventory transactions during the month of July. All of the units sold were priced at $20 per unit. Required: a. Glassworks Ltd. uses the perpetual inventory system. Calculate Glassworks' cost of goods sold, gross margin, and ending inventory for the month of July using i. FIFO ii. weighted-average b. Which of the cost flow assumptions would produce the higher gross margin