1. Diaz Company sold 180 units @ $80 each on October 31, 2011. The following information is also available: Beginning inventory 40 units @ $20 per unit Feb 3 - Purchase 60 units @ $30 per unit June 2- Purchase 70 units @ $40 per unit Oct 1 40 units @ $50 per unit Required a. Calculate the cost of goods sold using the Weighted Average Method. b. Calculate the Gross Margin