XYZ Corp. reported the following financial data for the year ending December 31, 2012: Net sales: $5,000,000 Gross profit: $3,000,000 Operating expenses: $1,500,000 Interest expense: $200,000 Income tax expense: $500,000 Net income: $800,000 Calculate the following ratios for XYZ Corp.: a. Gross profit margin b. Operating profit margin c. Net profit margin d. Return on assets e. Return on equity