The mean of a distribution with probability density function 
is the first raw moment 
, defined by
 |
(1)
|
where 
is the expectation value.
For a continuous distribution function, the population mean is given by
 |
(2)
|
where 
is the expectation value. Similarly, for a discrete distribution,
 |
(3)
|
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.
