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LaTeX Math Block
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\bar \mu_n = \frac{\mu_n}{\sigma^n} E[ ( x -, \ \mu)^n ] = \frac{1}{N} \sum_{i=1}^N (x_i - \mu)^n n \geq 3

where 

LaTeX Math Inline
bodyN

LaTeX Math Inline
bodyE

LaTeX Math Inline
body\mu_n

n-order of central momentum

LaTeX Math Inline
body\sigma


The common assumption is that zero-th central momentum is unit-value: concept makes sense only for the central momentums of higher oder than 

LaTeX Math Inline
bodyn \geq 3
, since lower order central momentums  
LaTeX Math Inline
body\bar \mu_0 \equiv 1
.By definition the first central momentum is always zero: 
/\sigma
,
LaTeX Math Inline
body\bar \mu_1 \equiv 0
.The second central momentum (μ2) is also called variance ,
LaTeX Math Inline
body--uriencoded--\bar \mu_2 = \sigma%5e2
, where 
LaTeX Math Inline
body\sigma
 is standard deviation.
equiv 1
 are trivial and do not carry additional information on dataset distribution.


The most popular application is the 3-rd order 

The third central momentum is characterizing asymmetry of the variance 

LaTeX Math Inline
body--uriencoded--\mu_3 = \bar \mu_3 \cdot \sigma%5e3
, where 
LaTeX Math Inline
body\bar \mu_3
 is skewness.

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