If there is an error of 0.1% in the measurement of the radius of a sphere, find approximately the percentage error in the calculation of the volume of the sphere.
Let x be the radius and y be the volume of the sphere.
$y=\frac{4}{3} \pi x^{3}$
Let $\Delta x$ be the error in the radius and $\Delta y$ be the error in the volume.
Then, $\frac{\Delta x}{x} \times 100=0.1$
$\Rightarrow \frac{d x}{x}=\frac{1}{1000}$
Now, $y=\frac{4}{3} \pi x^{3}$
$\Rightarrow \frac{d y}{d x}=4 \pi \mathrm{x}^{2}$
$\Rightarrow \mathrm{dy}=4 \pi \mathrm{x}^{2} \mathrm{dx}$
$\Rightarrow \frac{\mathrm{dy}}{\mathrm{y}}=\frac{4 \pi \mathrm{x}^{2} \mathrm{dx}}{\frac{4}{3} \pi \mathrm{x}^{3}}=\frac{3}{\mathrm{x}} \mathrm{dx}$
$\Rightarrow \frac{\mathrm{dy}}{\mathrm{y}}=\frac{3}{1000}$
$\Rightarrow \frac{\Delta \mathrm{y}}{\mathrm{y}} \times 100=0.3$
Hence, the percentage error in the calculation of the volume of the sphere is 0.3.