Yarrington has played the long game at Chevron. She joined the company in 1980 after earning her MBA at Northwestern, and spent three decades climbing the ranks to the CFO spot in 2009. One of her core business beliefs, she said in a recent speech, has been persistence. "Take the long view," she said. "Don't get caught up worrying about climbing the career ladder as fast as you can." The fruits of her patience? One of the most important jobs at the country's second-largest oil company, and the fourth highest paid.