Ya I'm not sure, but I would have to think there are some GMATclubbers around that got in with below. If there are any out there chime in
The people above 700 may have been part of the USC full time, but there are definitely people that go to USC.PM with over 700 (including a friend of mine).
As far as the 80% GMAT is concerned, we use this as a range to show you what your GMAT score should look like to have a decent shot of getting in. This is not to say that people above or below this range would not get in, but normally the school only takes 10% below the range and 10% above the range. So if there is a class of 300, there would be approx 30 people that have less than the 80% range and 30 people above (just an estimate). But this doesn't mean that someone below Anderson's 80% range would definitely have no chance to get in, and if you were above it is no guarantee that you would get in. But if you are below you would most likely have to bring something very special somewhere else in your application. Schools are ranked partially on GMAT average, median, etc... so if they let people in with low GMAT or low GPA, they will probably want you to have something special somewhere else.
So I would always encourage someone to apply if they are atleast close to the 80% range, but just realize, it will be more challenging if your GMAT is below the 80% range. It would be recommended that you retake and attempt to get a higher GMAT to improve your chances if you have the time. Anderson's Median GMAT is 690, so I would think that close to half their class will have over a 700+.
It doesn't appear that anyone reporting on GMATclub had below the 80% range at Anderson, but follow the page here:
anderson-femba-2012-calling-all-applicants-120316.html if you are interested.
If you have any other questions I'd be happy to give my advice. Best of luck to you