The Shirt Shop had the following transactions for T-shirts for Year 1, its first year of operations. January 20 $3,690 2,600 April 21 July 25 September 19 Purchased 460 units - Purchased 260 units $10- Purchased 340 unite e $13- Purchased 150 unite # $15- 4,420 2,250 During the year, The Shirt Shop sold 990 T-shirts for $24 each. Compute the difference in gross margin between the FIFO and LIFO cost flow assumptions.