July	August	September
Sales in units	30,000	60,000	90,000
Sales	$18,000,000	$36,000,000	$54,000,000
Cost of goods sold	13,500,000	27,000,000	40,500,000
Gross Margin	4,500,000	9,000,000	13,500,000
Selling, distribution and administrative expenses:
Advertising expenses	250,000	250,000	250,000
Selling expenses	300,000	450,000	600,000
Shipping expenses	285,000	570,000	855,000
Administrative office supplies	1,200,000	2,250,000	3,300,000
Salaries and Commission	900,000	1,800,000	2,700,000
Insurance expenses	100,000	100,000	100,000
Depreciation expenses	190,000	190,000	190,000
Total Selling & Admin expenses	3,225,000	5,610,000	7,995,000
Operating income	1,275,000	3,390,000	5,505,00

1. Identify each of the companys expenses (including cost of goods sold) as either variable, fixed or mixed

2. Using the high-low method, separate each mixed expense into variable and fixed elements. State the cost formula for each mixed expense.

3. Redo the companys income statement for September using the contribution format