Question

What mean standard deviation?

Answer 1

Standard deviation:

Standard deviation is a measure of the dispersion of a set of data from its mean.

It is denoted by the symbol $\sigma$.

Formula: $\sigma =\sqrt{\frac{{\displaystyle \sum _{i=1}^n{\left(x_i-\mu \right)}^2}}{n}}$ where $\mu$ is a population mean, $n$ is the total number of observations, and $x_i$ is the $i^{th}$ observation.