Question

The sum of all X's is 3780. The sum of all X^2 is 80000. The sample N = 180. How can I calculate the variance?

Answer 1

The variance is `=442`

Explanation:

`sumx=3780`

`sumx^2=80000`

`n=180`

`barx=(sumx)/n=3780/180=21`

`V(x)=(sumx^2-barx^2)/180`

`=(80000-21^2)/180=79559/180=442`