# Thread: Average of absolute sample proportional to StdDev?

1. ## Average of absolute sample proportional to StdDev?

Hello,
I have many samples normally distributed with mean=0.
When I take the absolute values of all the samples and calculate the average A, I find that the StdDev is always 1.254A.
Can you explain why?
Thanks,
Shai

2. ## Re: Average of absolute sample proportional to StdDev?

Please attend to precision when asking questions of this nature. A "sample" is a set of data collected from a statistical population. A sample consists of elements, typically called observations. You claim to have "many samples normally distributed with mean=0." I am guessing that you meant to say you have many observations sampled from a population that is normally distributed with mean 0? Or does the data in your sample appear normal and the sample mean is zero?

Clear this up and we can proceed.