I specifically said that I'm not talking about the average. An average would make it so that people would try actively to not get low ranking players into their clan. The "weighted sum" (or whatever it is I'm talking about) would make it so that low ranking players wouldn't have a significant effect on the rank of the clan if higher ranked players are already members, but they wouldn't pull the rank down. Thus, there's no reason not to have them in your clan.