By almost every educational measure, the Agora Cyber Charter School is failing, the New York Times reports. Nearly 60 percent of its students are behind grade level in math. Nearly 50 percent trail in reading. A third do not graduate on time. And hundreds of children, from kindergartners to seniors, withdraw within months after they enroll. By Wall Street standards, though, Agora is a remarkable success that has helped enrich K12 Inc [1]., the publicly traded company that manages the school. And the entire enterprise is paid for by taxpayers. Agora is one of the largest in a portfolio of similar public schools across the country run by K12. Eight other for-profit companies also run online public elementary and high schools, enrolling a large chunk of the more than 200,000 full-time cyberpupils in the United States…