Tree Seedlings has the following current-year purchases and sales for its only product. Date Activities Units Acquired at Cost Units Sold at Retail 42 units @ $2 - $ 84 32 units @ $8 76 units @ $3 = $ 228 Jan. 1 Beginning inventory Jan. 3 Sales Feb. 14 Purchase Feb. 15 Sales June 30 Purchase Nov. 6 Sales Nov. 19 Purchase 68 units @ $8 160 units @ $4 $ 640 90 units @ $8 24 units @ $5 $ 120 $1,072 Totals 302 units 190 units Required: The company uses a periodic 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