Hi;

I know the formula for variance and that a low value means the data is more compact

and a larger value means spread out more.

But what does the value actually relate to?

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- May 26th 2013, 03:58 AManthonyevariance value
Hi;

I know the formula for variance and that a low value means the data is more compact

and a larger value means spread out more.

But what does the value actually relate to? - May 26th 2013, 06:08 AMHallsofIvyRe: variance value
Pretty much just what you said: how much the data "varies" or is spread out. Essentially, it tells us how "random" the data is.

- May 26th 2013, 10:07 AMMINOANMANRe: variance value
It is a measure of spread

for more details look here..:

Variance - Wikipedia, the free encyclopedia - May 27th 2013, 10:20 AManthonyeRe: variance value
Variance,average distance to the mean squared so lets say I have a data set of

3,4,6,7 Therfore mean=5

variance=2.5. I get average distance as 2+1+1+2=6/4 1.5squared equals 2.25.

Why is this? - May 27th 2013, 11:11 AMShakarriRe: variance value
The average of several numbers which have been squared is not equal to the average of the numbers then squared.

Suppose you have 2 numbers a and b

The average of their squares is $\displaystyle \frac{a^2+b^2}{2}$

The square of their average is $\displaystyle (\frac{a+b}{2})^2=\frac{a^2+2ab+b^2}{4}$

You can see that they are different values.