Calculate a) cost of goods sold, b) ending inventory, and c) gross margin for B76 Company, considering the following transactions using perpetual inventory updating. Provide calculations for weighted average (AVG). Number of Units Unit Cost Sales Beginning inventory 420 $200 Sold 150 $401 Purchased 250 205 Sold 275 421 Purchased 200 215 Sold 260 441 Ending inventory 185