The population mean of a variate is its expectation value, when this value exists. It is the first raw
moment 
,
defined by
 |
(1)
|
where 
denotes the variate.
For a variate with probability density function 
,
the population mean is given by
 |
(2)
|
Similarly, for a discrete distribution,
 |
(3)
|
where the sum ranges over all possible values 
and 
is the probability of
.
The population mean of a distribution is implemented in the Wolfram Language as Mean[dist].
The sample mean is an unbiased estimator for the population mean.
