Plastic Extrusions Inc. had total assets of $1,000,000 at the end of Decem-ber. Liabilities were $250,000, and owners' equity was $750,000. During the year, sales totalled $5,000,000, operating income was $100,000, interest payments and taxes were $25,000, and net income was $75,000. Required Calculate the following: (a) The return on assets (b) The return on owners' equity