$\begin{align}  & mean=\overline{x}=\frac{x+2x+x+1+3x}{4} \\ & 2=\frac{7x+1}{4} \\ & 8=7x+1 \\ & x=1 \\ & \text{Therefore},\text{ the distribution is 1},\text{ 2},\text{ 2},\text{ 3} \\ & \text{mean deviation}=\frac{\left| 1-2 \right|+\left| 2-2 \right|+\left| 2-2 \right|+\left| 3-2 \right|}{4}=\frac{1+1}{4}=\frac{2}{4}=0.5 \\\end{align}$