Coefficient of variation $=\frac{\cdots}{\text { Mean }} \times 100$
$\text{CV}=\frac{S D}{\text { Mean }} \times 100$
If $\overline{\boldsymbol{x}}$ is the mean of $n$ values of $\boldsymbol{x}$, then $\sum_\limits{i=1}^n\left(\boldsymbol{x}_1-\overline{\boldsymbol{x}}\right)$ is always equal to .......... . If $a$ has any value other than $\overline{\boldsymbol{x}}$, then $\sum_\limits{i=1}^n\left(\boldsymbol{x}_i-\overline{\boldsymbol{x}}\right)^2$ is ................. than $\sum\left(x_i-a\right)^2$
If $\bar{x}$ is the mean of $n$ values of $x$, then $\sum_\limits{i=1}^n\left(x_i-\bar{x}\right)=0$ and if a has any value other than $\bar{x}$, then $\sum_\limits{i=1}^n\left(x_i-\bar{x}\right)^2$ is less than $\sum\left(x_i-a\right)^2$.
If the variance of a data is 121 , then the standard deviation of the data is ............ .
If the variance of a data is 121.
Then,
$$\begin{aligned} \mathrm{SD} & =\sqrt{\text { Variance }} \\ & =\sqrt{121}=11 \end{aligned}$$
The standard deviation of a data is ........... of any change in origin but is ............. of change of scale.
The standard deviation of a data is independent of any change in origin but is dependent of change of scale.
The sum of squares of the deviations of the values of the variable is ........... when taken about their arithmetic mean.
The sum of the squares of the deviations of the values of the variable is minimum when taken about their arithmetic mean.