Tree Seedlings has the following current-year purchases and sales for its only product. Date Activities Jan. 1 Beginning inventory Jan. 3 Sales Feb. 14 Purchase Feb. 15 Sales June 30 Purchase Nov. 6 Sales Nov. 19 Purchase Totals Units Sold at Retail Units Acquired at Cost 150 units @ $2 = $ 300 106 units @ $8 228 units @ $3 = $ 684 170 units @ $8 200 units @ $4 = $ 800 152 units @ $8 64 units $5 642 units = $ 320 $2,104 428 units Required: The company uses a perpetual inventory system. a. Determine the costs assigned to ending inventory and to cost of goods sold using FIFO. b. Determine the costs assigned to ending inventory and to cost of goods sold using LIFO. c. Compute the gross margin for each method.