I'm very suprised about this result; I assumed a result of 80% to 90% or so.
Since 1985 I'm developer. In 2007 and 2008 I wrote some business components. Now I had time to study EJB's in depth (more than 3 month, 8 hours a day). My material was Enterprise JavaBeans 3.0 (O'Reilly), EJB3 in action (Manning), Enterprise JavaBeans 3.0 mit Eclipse und JBoss (mitp, german book), Mikala Zaikin's study guide and uncounted web ressources like Torsten Horn's Techdocs (written in German). Also I tried much programmcode using NetBeans and Glassfish2.