Revenue and expense data for Martinez Company are as follows: 2012 2011 Administrative expenses $37,000 $20,000 Cost of goods sold 350,000 320,000 Income tax 40,000 32,000 Net sales 800,000 700,000 Selling expenses 150,000 110,000 (a) Prepare a comparative income statement, with vertical analysis, stating each item for both 2012 and 2011 as a percent of sales. (b) Comment upon significant changes disclosed by the comparative income statement.