- #1
phoenixthoth
- 1,605
- 2
Why is the standard deviation [tex]\sigma =\sqrt{\frac{\sum_{i=1}^{n}\left( \overline{x}-x_{i}\right) ^{2}}{n-1}}[/tex] and not [tex]\sigma =\frac{\sum_{i=1}^{n}\left| \overline{x}-x_{i}\right| }{n}[/tex] or at least [tex]\sigma =\sqrt{\frac{\sum_{i=1}^{n}\left( \overline{x}-x_{i}\right) ^{2}}{n}}[/tex]?
I suppose that it has something to do with the normal distribution but I'm not sure in what way.
Thanks for the input.
I suppose that it has something to do with the normal distribution but I'm not sure in what way.
Thanks for the input.