WOLFRAM|DEMONSTRATIONS PROJECT

The Hypergeometric Distribution

​
sample size n
20
number of marked balls k
25
total number of balls N
100
mean:
kn
N
=
5.00
variance:
kn1-
k
N
(-n+N)
(-1+N)N
=
3.03
If
n
balls are sampled without replacement from a bin containing
N
balls, of which
k
are marked, then the distribution of the number of marked balls in the sample follows a hypergeometric distribution.