i was looking for eragon bookmarks on the google and when i typed in eragon book 4 release date poped up and i clicked on it and wiki showed up and said book 4 will be out in agust but i don't belive it. Check youself.

It's not going to be out in August. The publisher will announce the date, until then we'll have to wait. It's not official unless it's from the author's or the publisher's people. Anything else is just rumor.
When the staff hear it, we'll announce it anyway, like we did for book 3.