what is the Return on common stockholder's equity?

Selected financial statement data for Homer Company are presented below. Net Sales $1,500,000 Cost of goods sold 700,000 Interest expense 10,000 Net income 205,000 Total assets (ending) 900,000 Total common stockholder's equity (ending) 600,000 Total assets at the beginning of the year were $800,000; total common stockholders' equity was $500,000 at the beginning of the period