What is the mean deviation of first 10 even natural numbers?

First 10 Even Natural numbers are 2, 4, 6, 8, 10, 12, 14, 16,18 and 20. Mean, $\bar{x}=\frac{\sum x_i}{n}=\frac{2+4+6+\ldots+20}{10}$$\begin{aligned} & \bar{x}=\frac{2(1+2+3+\ldots+10)}{10} \\ & \bar{x}=\frac{1}{5} \times \frac{10(10+1)}{2}=11 \end{aligned}$$\rightarrow$ Now, To calculate Mean deviation, we should calculate $x i-\bar{x}$ for each observation. $$\begin{aligned} & x i-:-9,-7,-5,-3,-1,1,3,5,7,9 \\ & |x i-|: 9,7,5,3,1,1,3,5,7,9 \end{aligned}$$\therefore$Mean deviation, M.D.$=\frac{\sum|x i-\bar{x}|}{n}$$\begin{aligned} & \text{ M.D. }=\frac{9+7+5+3+1+1+3+5+7+9}{10} \\ & \text{ M.D. }=\frac{2(1+3+5+7+9)}{10}=\frac{2 \times 25}{10} \\ & \text{ M.D. }=5 \end{aligned}$$$