$\overline{\mathrm{x}}=\frac{\sum {\mathrm{f}}_{\mathrm{i}}{\mathrm{x}}_{\mathrm{i}}}{\sum {\mathrm{f}}_{\mathrm{i}}}=6\Rightarrow \mathrm{P}\to 3\mathrm{N}=20,\frac{\mathrm{N}}{2}=10$
Median = Size of observation whose cumulative frequency just greater than or equal to 10= 5 $\Rightarrow \mathrm{Q}\to 2$
Median deviation about mean $=\frac{{\mathrm{\Sigma f}}_{\mathrm{i}}\left|{\mathrm{x}}_{\mathrm{i}}-\overline{\mathrm{x}}\right|}{{\mathrm{\Sigma f}}_{\mathrm{i}}}=2.7\Rightarrow \mathrm{R}\to 4$
Mean deviation about median $=\frac{{\mathrm{\Sigma f}}_{\mathrm{i}}\left|{\mathrm{x}}_{\mathrm{i}}-\mathrm{M}\right|}{{\mathrm{\Sigma f}}_{\mathrm{i}}}=2.4 \Rightarrow \mathrm{S}\to 5$