Population:

Ω = {4, 7, 5, 7, 7, 8, 6, 3, 6, 5},         = 5.8

,                    

 

Sample:

X = {7, 5, 8, 6, 6},      X = 6.4

,        ,        sample variation

,        ,        population variation

 

i-)2

(xi-X)2

4 3.24  
7 1.44  
5 0.64 1.96
7 1.44 0.36
7 1.44  
8 8.84 2.58
6 0.04 0.16
3 7.84  
6 0.04 0.16
5 0.64  
11 5.22

 

The sum of the distance squares in the sample is apart from some random exceptions smaller than the same values in the whole population.

 

Thanks to Klaus Jung for the exemplification.