Seattle-area education technology company DreamBox Learning sold a majority stake to Evergreen Coast Capital Corp., a tech-focused Silicon Valley affiliate of private equity firm Elliott Investment Management. Terms of the deal were not disclosed. Founded in 2006, DreamBox sells software to K-12 schools. The company’s technology adapts to individual students based on their answers and how they solve problems. Teachers and administrators get access to analytics and reporting. The 400-person company, ranked No. 18 on the GeekWire 200, supports 6 million students and 400,000 educators. DreamBox said its annual revenues are on target for more than $100 million.