Hi TheLostOne,
In real simple terms, the answer to your question is YES - the sample that you're seeing is NOT properly representative of the overall pool.
Assuming that you know how to calculate an average, then you should understand that a Program's AVERAGE GMAT score implies an acceptable 'range' of GMAT scores for that School, so to be competitive, you need a score that is 'in the range' (and not necessarily one that's equal to, or higher than, the average). At highly competitive Programs, the OVERALL application matters, so you have to be a strong overall applicant AND you have to present yourself correctly to each Admissions Committee.
This is all meant to say that you shouldn't worry about anyone else who's applying - focus on making YOUR application as strong as you can. To that end...
1) Have you taken the GMAT? How have you scored?
2) What Business Schools are you planning to apply to?
3) When are you planning to apply?
GMAT assassins aren't born, they're made,
Rich