# Definition:Expectation of Random Vector

Let $X_1, X_2, \ldots, X_n$ be random variables on a probability space $\left({\Omega, \Sigma, \Pr}\right)$.
Let $\mathbf X = \left({X_1, X_2, \ldots, X_n}\right)$ be a random vector.
Then the expected value of $\mathbf X$, $\mathbb E \left[{\mathbf X}\right]$, is defined by:
$\mathbb E \left[{\mathbf X}\right] = \left({\mathbb E \left[{X_1}\right], \mathbb E \left[{X_2}\right], \ldots, \mathbb E \left[{X_n}\right]}\right)$