The'''Moment about the mean''' ''k''<sup>th</sup> '''moment about the mean''' (oratawa ''k''<sup>th</sup> '''central moment''') of a nilai-real-valued [[random variable]] ''X'' isnyaeta the quantitykuantitas E[(''X'' − E[''X''])<sup>''k''</sup>], wherenumana E is thengarupakeun [[expected value|expectation operator]]. SomeSababaraha randomvariabel variablesrandom haveteu nongabogaan [[mean]], indina whichkasus case the moment about themomen mean isteu notbisa defineddiartikeun. TheMomen mean ''k''<sup>th</sup> moment about the mean issalawasna oftendilambangkeun denotedku μ<sub>''k''</sub>. ForKeur a continuous univariate [[probability distribution]] withnu mibanda [[probability density function]] ''f''(''x'') the moment about themomen mean μ isnyaeta
:<math>
Baris ka-7:
</math>
Kadangkala kacida pasna keur koversi momen asli ka momen mean. Persamaan umum keur konversi momen asli orde-n<sup>th</sup> ka momen mean nyaeta
Sometimes it is convenient to convert moments about the origin to moments about the mean. The general equation for converting the n<sup>th</sup>-order moment about the origin to the moment about the mean is
:<math>
Baris ka-13:
</math>
wherenumana <em>m</em> is thengarupakeun mean of the distributionsebaran, and the moment aboutsarta themomen originasli isdirumuskeun givenku by
:<math>
Baris ka-19:
</math>
TheMomen firstmean momentkahiji aboutnyaeta the mean is zeronol. The second moment about theMomen mean iskadua called thedisebut [[variance]], andbiasa isdilambangkeun usually denotedku σ<sup>2</sup>, wherenumana σ represents thengawakilan [[standard deviationsimpangan]]. The third and fourth moments about theMomen mean arekatilu usedjeung tokaopat define thengartikeun [[standardized moment]]swhichsacara are"berurutan" indipake turnkeur used to definengartikeun [[skewness]] andjeung [[kurtosis]], respectively.
