Comparative income statements for 2012 and 2011 follow. Sales Cost of Sales Gross Profit 2012 2011 $9,434,000 $7,862,000 7,075,400 5,660,640 $2,358,600 $2,201,360 1,367,690 1,365,060 Operating Expenses Operating Income Interest Expense Earnings Before Tax Income Taxes Net Income Required: a. b. $ 990,910 157,500 $ 836,300 126,000 $ 710,300 317,200 $ 833,410 400,000 $ 433,410 $ 393,100 Prepare a vertical common-size analysis of this statement for each year, using sales as the base. Comment briefly on the changes between the two years, based on the vertical common-size statement.