Sample: 4 5 3 6 5 6 5 6
When I do the long method for sample variance I got 1.14, but when I tried the shortcut method, it is giving me a different answer..
s^2= (1/n-1)(Σ xi^2-(Σ xi^2)/n))
s^2= 1/7[208-(1600/7)]
s^2= -2.93
I am not sure what is going wrong..
Hmmm. Parentheses make a difference. Try
1/(n-1) (Σx^2 -(Σx)^2/n)