The following information was available for the year ended December 31, 2019:
Sales $ 530,000
Net income 77,260
Average total assets 840,000
Average total stockholders' equity 385,000
Dividends per share 1.37
Earnings per share 3.00
Market price per share at year-end 28.80

Calculate margin, turnover, and ROI for the year ended December 31, 2019.