In statistics, the variance is a measure of how spread out a set of data is from its mean value. The variance is often denoted using the symbol $\sigma^2$.

Variance symbol in LaTeX

In statistics, the variance symbol is used to represent the spread of data around the mean. In LaTeX, the variance symbol can be represented using the command \sigma^2.

To write the variance symbol in LaTeX, use the following command:

$$\sigma^2$$
\[\sigma^2\]

This represents the variance symbol $\sigma^2$. It is also common to use the square root of the variance, represented by the symbol $\sigma$ without the exponent 2.

To write the square root of the variance in LaTeX, use the following command:

$$\sqrt{\sigma^2}$$
\[\sqrt{\sigma^2}\]

This represents the square root of the variance $\sqrt{\sigma^2}$.

Here are some examples of using the \sigma^2 command:

$$\sigma^2 = \frac{1}{n} \sum_{i=1}^n (x_i - \bar{x})^2$$
\[\sigma^2 = \frac{1}{n} \sum_{i=1}^n (x_i - \bar{x})^2\]

This represents the formula for variance, where $\bar{x}$ is the sample mean.

$$Y = aX + b + \epsilon, \quad \epsilon \sim \mathcal{N}(0,\sigma^2)$$
\[Y = aX + b + \epsilon, \quad \epsilon \sim \mathcal{N}(0,\sigma^2)\]

This represents a linear regression model where the error $\epsilon$ follows a normal distribution with variance $\sigma^2$.

Remember that to use the \sigma^2 command in LaTeX, you need to include the amsmath package in the preamble of your LaTeX document.

That’s all there is to it!