Source: Houghton Mifflin Harcourt Publishing Company.
A conjecture is a statement that is believed to be true. It may or may not actually be true, it is believed to be true. A conjecture is sometimes referred to as an educated guess. In other words, it is guessing what comes next based on a pattern.
Follow the link below to watch a video by Dr Edward Berger about making conjectures.
http://my.hrw.com/math06_07/nsmedia/lesson_videos/geo/player.html?contentSrc=6520/6520.xml
Source: Houghton Mifflin Harcourt Publishing Company