Find the mean deviation about the median for the data
36, 72, 46, 42, 60, 45, 53, 46, 51, 49
The given data is
36, 72, 46, 42, 60, 45, 53, 46, 51, 49
Here, the number of observations is 10, which is even.
Arranging the data in ascending order, we obtain
36, 42, 45, 46, 46, 49, 51, 53, 60, 72
Median $\mathrm{M}=\frac{\left(\frac{10}{2}\right)^{t h} \text { observation }+\left(\frac{10}{2}+1\right)^{m} \text { observation }}{2}$
$=\frac{5^{\text {th }} \text { observation }+6^{\text {th }} \text { observation }}{2}$
$=\frac{46+49}{2}=\frac{95}{2}=47.5$
The deviations of the respective observations from the median, i.e. $x_{i}-\mathrm{M}$, are
–11.5, –5.5, –2.5, –1.5, –1.5, 1.5, 3.5, 5.5, 12.5, 24.5
The absolute values of the deviations, $\left|x_{i}-\mathrm{M}\right|$, are
11.5, 5.5, 2.5, 1.5, 1.5, 1.5, 3.5, 5.5, 12.5, 24.5
Thus, the required mean deviation about the median is
M.D. $(\mathrm{M})=\frac{\sum_{i=1}^{10}\left|x_{i}-\mathrm{M}\right|}{10}=\frac{11.5+5.5+2.5+1.5+1.5+1.5+3.5+5.5+12.5+24.5}{10}$
$=\frac{70}{10}=7$