## Variance and Standard deviation for ungrouped data

Use this calculator to find the variance and standard deviation for ungrouped (raw) data.

Variance and std. deviation Calculator
Enter the X Values (Separated by comma,)
Results
Number of Obs. (n):
Sample Mean : ($\overline{x}$)
Sample variance : ($s^2_x$)
Sample std. Deviation : ($s_x$)

## Variance and Standard deviation for ungrouped data

Use this calculator to find the variance and standard deviation for ungrouped (raw) data.

Let $x_i, i=1,2, \cdots , n$ be $n$ observations then the mean of $X$ is denoted by $\overline{X}$ and is given by $$\begin{eqnarray*} \overline{X}& =\frac{1}{n}\sum_{i=1}^{n}x_i \end{eqnarray*}$$ Variance of $X$ is denoted by $s_{x}^2$ and is given by \begin{aligned} s_x^2 & =\frac{1}{n-1}\sum_{i=1}^{n}(x_i -\overline{x})^2\\ &=\frac{1}{n-1}\bigg(n\sum_{i=1}^{n} x_i^2-\big(\sum_{i=1}^nx_i\big)^2\bigg) \end{aligned}

The standard deviation of $X$ is defined as the positive square root of variance. The standard deviation of $X$ is given by

$$\begin{eqnarray*} s_x & =\sqrt{s_x^2} \end{eqnarray*}$$