Question

Find out mean deviation of the monthly income of the five families given below, using arithmetic mean of the data:
852, 635, 792, 836, 750

Answer 1

Sr. No.	Monthly Income (X)	Deviation from Arithmetic mean $\left|{\mathit{d}}_{\overline{\mathbf{X}}}\right|\mathbf{=}\left|\mathit{X}\mathbf{-}\overline{\mathit{X}}\right|$ $\overline{\mathit{X}}=$773
1 2 3 4 5	852 635 792 836 750	852-773=79 138 19 63 23
N=5	ΣX = 3865	$\mathrm{\Sigma }\left|d_{\overline{X}}\right|=322$

$$\begin{gathered} \mathrm{Mean}\left(\overline{X}\right)=\frac{\Sigma X}{N}=\frac{3865}{5}=773 \\ \mathrm{Mean}\mathrm{deviation}M{D}_{\overline{x}}=\frac{\mathrm{\Sigma }\left|d_{\overline{X}}\right|}{N}=\frac{322}{5}=64.4 \end{gathered}$$

Hence, mean deviation of the monthly income is 64.4.