$\begin{aligned} & M=(0.6 \pm 0.006) g \\ & r=(0.5 \pm 0.005) \mathrm{mm} \\ & I=(4 \pm 0.04) \mathrm{cm} \\ & \left.\rho=\frac{m}{V} \right\rvert\, \\ & \frac{\Delta \rho}{\rho}=\frac{\Delta m}{m}+\frac{2 \Delta r}{r}+\frac{\Delta l}{I} \\ & \left(\text { Volume of cylinder }=\pi r^2 I\right) \\ & =\frac{0.006}{0.6}+\frac{2 \times 0.005}{0.5}+\frac{0.04}{4} \\ & 100 \times \frac{\Delta \rho}{\rho}=4 \times 10^{-2} \times 100 \\ & \frac{\Delta \rho}{\rho} \times 100=4 \%\end{aligned}$