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 July 25 September 19 Purchased 390 units @ $3 Purchased 110 units @ $4= Purchased 230 units @ $6 Purchased 90 units @ $8- During the year, The Shirt Shop sold 620 T-shirts for $13 each. $ 1,170 440 1,380 720 b. Compute the difference in gross margin between the FIFO and LIFO cost flow assumptions. Gross margin FIFO LIFO Difference 780