## Precalculus (6th Edition) Blitzer

The angle of inclination of the ramp with the horizontal is $18{}^\circ$. On resolving the vector into its horizontal and vertical components, the horizontal component will get cancelled and we get \begin{align} & \sin 18{}^\circ =\frac{30}{x} \\ & x\sin 18{}^\circ =30 \\ & x=\frac{30}{\sin 18{}^\circ } \\ & =97.1\text{ pounds} \end{align} So, the weight of the box is $97.1\text{ pounds}$.