## Math-Linux.com

Knowledge base dedicated to Linux and applied mathematics.

Home > Latex > FAQ > Latex - FAQ > Latex expected value symbol - expectation

# Latex expected value symbol - expectation

Expected value or expectation of a random variable $X$ is defined, if it exists, in a mathematically precise way with respect to a probability space, typically denoted as $(\Omega, \mathcal{A}, \mathbb{P})$, where $\Omega$ is the universe of possibilities, $\mathcal{A}$ the set of possible events (which are the possible values of the random variable $X$) and $\mathbb{P}$ a probability measure such that $\mathbb{P}(\Omega)=1$.

## Latex expected value using mathbb function

To use the latex expected value using mathbb function, you must load amssymb package


\documentclass[12pt]{article}
\usepackage{amssymb}
...
\end{document}



Next, we use \mathbb function.

Here are five examples using LaTeX to write expected value of a random variable $X$ :


\documentclass[12pt]{article}
\usepackage{amssymb}
$$\mathbb{E}[X] = \sum_{i=1}^{n} x_i \cdot p_i$$

$$\mathbb{E}[X] = \frac{\displaystyle\sum_{i=1}^{n} x_i \cdot p_i}{\displaystyle\sum_{i=1}^{n} p_i}$$

$$\mathbb{E}[X] = \int_{-\infty}^{\infty} xf(x) \, dx$$

$$\mathbb{E}[X] = \frac{1}{n} \sum_{i=1}^{n} x_i$$

$$\mathbb{E}[X] = \int_{-\infty}^{\infty} x \, dF(x)$$
\end{document}



$$\mathbb{E}[X] = \sum_{i=1}^{n} x_i \cdot p_i$$

$$\mathbb{E}[X] = \frac{\displaystyle\sum_{i=1}^{n} x_i \cdot p_i}{\displaystyle\sum_{i=1}^{n} p_i}$$

$$\mathbb{E}[X] = \int_{-\infty}^{\infty} xf(x) \, dx$$

$$\mathbb{E}[X] = \frac{1}{n} \sum_{i=1}^{n} x_i$$

$$\mathbb{E}[X] = \int_{-\infty}^{\infty} x \, dF(x)$$