For the year ended September 26, 2015, Apple, Inc., reported net income of $53,394 million. Total shareholders' equity on this date was $119,355 million, and on September 27, 2014, it was $111,547 million. No preferred stock was outstanding in either year.

Required

1. Compute Apple's return on common stockholders' equity for the year ended September 26, 2015.

2. What other ratio would you want to compute to decide whether Apple is successfully employing leverage? Explain your answer.