P-F:6-33B Accounting for inventory using the perpetual inventory system-FIFO, LIFO, and weighted-average (Learning Objectives 2, 3) Exercise World began January with merchandise inventory of 90 crates of vitamins that cost a total of $5,850. During the month, Exercise World purchased and sold merchandise on account as follows: P-F:6-33B Accounting for inventory using the perpetual inventory system-FIFO, LIFO, and weighted-average (Learning Objectives 2, 3) Exercise World began January with merchandise inventory of 90 crates of vitamins that cost a total of $5,850. During the month, Exercise World purchased and sold merchandise on account as follows