Definition:Raw Moment

Definition
Let $X$ be a random variable on some probability space.

Then the $n$th raw moment of $X$, usually denoted $\mu'_n$, is defined as:


 * $\mu'_n = \expect {X^n}$

where $\expect X$ denotes the expectation of $X$.

That is, the $n$th raw moment of $X$ is its $n$th moment about $0$.

The first raw moment of $X$ is the mean of $X$, and is instead usually denoted $\mu$.

Also known as
Some sources refer to the raw moment of a random variable as its moment about the origin.

Also see

 * Definition:Moment (Probability Theory)
 * Definition:Central Moment
 * Definition:Standardized Moment