Three identical units of merchandise were purchased during July, as follows:

	Date	Product Basic H	Units	Cost
	July 3	Purchase	1	$35
	10	Purchase	1	36
	24	Purchase	1	37
		Total	3	$108
		Average cost per unit		$36

Assume one unit sells on July 28 for $45.

Determine the gross profit, cost of goods sold, and ending inventory on July 31 using (a) first-in, first-out, (b) last-in, first-out, and (c) average cost flow methods.