Question

Mean deviation for $n$ observations $x_1,x_2,.....x_n$ from their mean $\overline{X}$ is given by:

• A. ${\sum }_{i=1}^n(x_i-\overline{X})$
• B. $\frac{1}{n}{\sum }_{i=1}^n|x_i-\overline{X}|$
• C. ${\sum }_{i=1}^n{{(x}_i-\overline{X})}^2$
• D. $\frac{1}{n}{\sum }_{i=1}^n{{(x}_i-\overline{X})}^2$

Answer 1

The correct option is B $\frac{1}{n}{\sum }_{i=1}^n|x_i-\overline{X}|$

It is fundamental concept that mean deviation of $n$ observations $x_1,x_2,x_3,......x_n$ about mean $\overline{X}$ is given by, $\frac{1}{n}\sum _{i=1}^{i=n}|x_i-\overline{X}|$