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Question 4 Your answer is partially correct. Try again. Sunland Window Cleaners' monthly income statement at several levels of activity is as follows: Windows washed 2,000 4,2008,600 Sales revenue $ 3,500 $ 7,350 $ 15,050 Cost of goods sold 1,400 2,940 6,020 Gross profit 2,100 4,410 9,030 Operating expenses Advertising expense 400 400 400 Salaries and wages expense 700 920 1,360 Insurance expense 200 200 200 Postage expense 420 882 1,806 Total operating expense 1,720 2,402 3,766 Operating income $ 380 $ 2,008 $ 5,264 (a) Identify each expense as fixed, variable, or mixed. Cost of goods sold T variable Advertising fixed Salaries and Wages T mixed Insurance fixed Postage variable (b) Prepare a contribution margin income statement based on a volume of 6,900 windows. (Round unit cost to 2 decimal places, e.g. 52.75 and all other answers to 0 decimal places, e.g. 5,275.) 6,900 windows Per Unit T Sales Revenue T Variable Expenses : Cost of Goods Sold : 05 | Salaries Expense T Postage Expense | T Total Variable Expenses T Contribution Margin Fixed Expenses Advertising Expense : Salaries Expense T Insurance Expense T Total Fixed Expenses TOperating Income