The Shirt Shop had the following transactions for T-shirts for Year 1, its first year of operations: $ 3,300 January 201 April 21 July 25 September 19 Purchased 330 units @ $10 = Purchased 80 units @ $11 = Purchased 210 units @ $13 = Purchased 60 units @ $14 880 2,730 840 During the year. The Shirt Shop sold 520 T-shirts for $19 each. b. Compute the difference in gross margin between the FIFO and LIFO cost flow assumpticas.