Required information [The following information applies to the questions displayed below.] The Shirt Shop had the following transactions for T-shirts for Year 1, its first year of operations. January 20 April 21 Purchased 400 units Purchased 200 units $10 $8 $3,200 2,000 July 25 Purchased 280 units @ $13 3,640 September 19 Purchased 90 units @ $15 1,350 During the year, The Shirt Shop sold 810 T-shirts for $20 each. c. Compute the difference in gross margin between the FIFO and LIFO cost flow assumptions. Difference in gross margin between the FIFO and LIFO cost flow assumptions