Three identical units of merchandise were purchased during July, as follows: Units Cost July 3 Purchase 1 $33 10 Purchase 1 36 24 Purchase 1 39 Total 3 Average cost per unit $108 $36 Assume one unit sells on July 28 for $51. Determine the gross profit, cost of merchandise sold, and ending inventory on July 31 using the (a) first-in, first-out, (b) last-in, first-out, and (c) weighted average cost flow methods a. First-in, first-out Gross Profit Cost of Merchandise Sold Ending Inventory b. Last-in, first-out c. Weighted average cost