1. Create a histogram and group the results together to whatever degree of accuracy you want (i.e. lump all people who answered 100 plus/minus 10 together into the "100" bin
2. Now if you plot this and squint you basically have a function f(x) where f is the number of clans and x is the size of the clan. f(x) is essentially the probability of finding a clan of size x.
3. Now we want to calculate the "expectation value" of x, or the average value of the size of the clan. This is usually done with an integrable function like this
[tex]\int^{\infty}_{\infty} x * f(x) dx[/tex]
Since we don't have a continuous function, you can use the summation:
[tex]\sum x P(x)[/tex]
Where P(x) is the probability of finding a clan of size x. Then you sum over all x's.
