Q.

∑i=110(xi-5)=5 and ∑i=110(xi-5)2=125, variance of x1,x2,…,x10 will be

1 94  
2 254  
3 494  
4 814  

Ans.

(3)

Let  xi-5=diσx2,  σd2=∑di2n-(∑din)2

=12510-(510)2

=252-14

=494