Confused...

Colour me confused, but how did this movie get a 4.2 rating when only two out of ten of the votes rated the movie below 6 (they voted 4)? The overall rating is supposed to be weighted average, yet it gives a much lower average than you would expect from the breakdown of ratings by vote.

Also, if you look at the breakdown by gender, age, etc. you'll notice that male voters ended up with a weighted average of 3.8. How does that happen when nobody listed has voted below a 4? Hello? Can anybody on IMDB answer this mystery? Or is this New Math of some nefarious type?

But then, what am I saying? Whoever made this happen is probably downright ecstatic that a nihilistic piece of toe-jam like Se7en is in the top hundred.