Sunland Medical manufactures hospital beds and other institutional furniture. The company's comparative balance sheet and income statement for 2019 and 2020 follow, 2019 Sunland Medical Comparative Balance Sheet As of December 31 2020 Assets Current assets Cash $398,000 Accounts receivable, net 1.099,000 Inventory 746,000 Other current assets 381,350 Total current assets 2,624,350 Property, plant, & equipment, net 8,645,055 $417.450 776,450 681,000 247.000 2.121,900 8.440,010 Total assets $11,269,405 $10,561.910 Liabilities and Stockholders' Equity Liabilities and Stockholders' Equity Current liabilities $3,209,000 $2,846,050 Long-term debt 3,702,600 3,892,700 Total liabilities 6,911,600 6,738,750 Preferred stock, $5 par value 59,000 59,000 Common stock, $0.25 par value 104,650 103,850 Retained earnings 4,194,155 3,660,310 Total stockholders' equity 4,357,805 3,823,160 Total liabilities and stockholders' equity $11,269,405 $10,561,910 Sunland Medical Comparative Income Statement and Statement of Retained Earnings For the Year 2020 2019 Sales revenue (all on account) $10,177,250 $9,613,900 Cost of goods sold 5,612,700 5,298,700 Gross profit 4,564,550 4,315,200 Operating expenses 2,840,300 2,634,200 Net operating income 1,724,250 1,681,000 Interest expense 300,400 308,700 Net income before taxes 1,423,850 1,372,300 Income taxes (30%) 427,155 411,690 Net income $996,695 $960,610 Dividends paid Preferred dividends 29,550 29,550 Common dividends 433,350 413,050 Total dividends paid 462,900 442.600 Net income retained 533,845 518,010 3,660,310 3,142,300 Retained earnings, beginning of year Retained earnings, end of year $4,194,155 $3,660,310 Calculate the following profitability ratios for 2020. (Round answers to 1 decimal place, e.g. 50.1%.) a. Gross margin percentage % b. Return on assets % C. Return on common stockholders' equity %