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

Sandhill Medical Comparative Balance Sheet As of December 31
		2020		2019
Assets
Current assets
Cash		$376,000		$417,500
Accounts receivable, net		1,055,000		776,400
Inventory		731,000		681,050
Other current assets		381,400		247,050
Total current assets		2,543,400		2,122,000
Property, plant, & equipment, net		8,720,425		8,439,980
Total assets		$11,263,825		$10,561,980
Liabilities and Stockholders' Equity
Current liabilities		$3,203,000		$2,846,100
Long-term debt		3,702,700		3,892,700
Total liabilities		6,905,700		6,738,800
Preferred stock, $5 par value		58,900		58,900
Common stock, $0.25 par value		104,600		103,800
Retained earnings		4,194,625		3,660,480
Total stockholders' equity		4,358,125		3,823,180
Total liabilities and stockholders' equity		$11,263,825		$10,561,980

Sandhill Medical Comparative Income Statement and Statement of Retained Earnings For the Year
		2020		2019
Sales revenue (all on account)		$10,177,200		$9,613,900
Cost of goods sold		5,612,200		5,298,750
Gross profit		4,565,000		4,315,150
Operating expenses		2,840,250		2,634,150
Net operating income		1,724,750		1,681,000
Interest expense		300,400		308,600
Net income before taxes		1,424,350		1,372,400
Income taxes (30%)		427,305		411,720
Net income		$997,045		$960,680
Dividends paid
Net income retained		534,145		518,080
Retained earnings, beginning of year		3,660,480		3,142,400
Retained earnings, end of year		$4,194,625		$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		%