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

Oriole Medical

Comparative Balance Sheet

As of December $31$

$20202019$

Assets

Current assets

Cash $$393,000$ $$417,400$

Accounts receivable, net $1,077,000776,450$

Inventory $735,000681,050$

Other current assets $381,400247,050$

Total current assets $2,586,4002,121,950$

Property, plant, & equipment, net $8,639,1608,440,060$

Total assets $$11,225,560$ $$10,562,010$

Liabilities and Stockholders$$ Equity

Current liabilities $$3,165,000$ $$2,846,050$

Long$-$term debt $3,702,6003,892,700$

Total liabilities $6,867,6006,738,750$

Preferred stock, $$5$ par value $58,95058,950$

Common stock, $$0\mathrm{.}25$ par value $104,650103,850$

Retained earnings $4,194,3603,660,460$

Total stockholders$$ equity $4,357,9603,823,260$

Total liabilities and stockholders$$ equity $$11,225,560$ $$10,562,010$

Oriole Medical

Comparative Income Statement and Statement of Retained Earnings

For the Year

$20202019$

Sales revenue $($all on account$)$ $$10,177,300$ $$9,613,950$

Cost of goods sold $5,612,8005,298,800$

Gross profit $4,564,5004,315,150$

Operating expenses $2,840,2002,634,150$

Net operating income $1,724,3001,681,000$

Interest expense $300,300308,700$

Net income before taxes $1,424,0001,372,300$

Income taxes $(30\%)427,200411,690$

Net income $$996,800$ $$960,610$

Dividends paid

Preferred dividends $29,55029,550$

Common dividends $433,350413,000$

Total dividends paid $462,900442,550$

Net income retained $533,900518,060$

Retained earnings, beginning of year $3,660,4603,142,400$

Retained earnings, end of year $$4,194,360$ $$3,660,460$

Calculate the following profitability ratios for $2020.($Round answers to $1$ decimal place, e$.$g$.50\mathrm{.}1\%.)$

a$.$ Gross margin percentage

$44\mathrm{.}8$

Correct answer$\%$

b$.$ Return on assets

$9\mathrm{.}15$

Incorrect answer$\%$

c$.$ Return on common stockholders$$ equity

$24\mathrm{.}0$

Correct answer. I need help on question B$.$ Everything else is correct.