CullumberMedical manufactures hospital beds and other institutional furniture. The company's comparative balance sheet and income statement for 2019 and 2020 follow.

CullumberMedical

Comparative Balance Sheet

As of December 3120202019AssetsCurrent assetsCash$400,000$417,500Accounts receivable, net1,056,000776,400Inventory721,000681,050Other current assets381,300247,050Total current assets2,558,3002,122,000Property, plant, & equipment, net8,710,1358,439,930Total assets$11,268,435$10,561,930Liabilities and Stockholders' EquityCurrent liabilities$3,208,000$2,846,000Long-term debt3,702,7003,892,650Total liabilities6,910,7006,738,650Preferred stock, $5 par value58,90058,900Common stock, $0.25 par value104,700103,900Retained earnings4,194,1353,660,480Total stockholders' equity4,357,7353,823,280Total liabilities and stockholders' equity$11,268,435$10,561,930

CullumberMedical

Comparative Income Statement and Statement of Retained Earnings

For the Year20202019Sales revenue (all on account)$10,177,300$9,613,900Cost of goods sold5,613,0005,298,700Gross profit4,564,3004,315,200Operating expenses2,840,2502,634,200Net operating income1,724,0501,681,000Interest expense300,400308,600Net income before taxes1,423,6501,372,400Income taxes (30%)427,095411,720Net income$996,555$960,680Dividends paidPreferred dividends29,50029,500Common dividends433,350413,100Total dividends paid462,850442,600Net income retained533,655518,080Retained earnings, beginning of year3,660,4803,142,400Retained earnings, end of year$4,194,135$3,660,480

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%