If the variance of the data 2, 3, 5, 8, 12 is σ² and the mean deviation from the median for this data is M then σ²–M =

Data 2, 3, 5, 8, 12
Median = 5
Mean deviation from median 
$=\frac{\sum \left|x-Median\right|}{n}=\frac{3+2+0+3+7}{5}$
$M=\frac{15}{5}=3$
Variance 

$\begin{array}{l}{\sigma }^2=\frac{\sum x^2}{n}-{\left(\frac{\sum x}{n}\right)}^2=\\ \frac{2^2+3^2+5^2+8^2+{12}^2}{5}\\ -{\left(\frac{2+3+5+8+12}{5}\right)}^2=13.2\end{array}$
${\sigma }^2-\mathrm{M}=10.2$