Answer
Boyle's law states that pressure and volume are indirectly proportional. A plot of $P$ vs. $\frac{1}{V}$ is required.
Charles's law states that temperature and volume are directly proportional. A plot of $T$ vs. $V$ is required.
Avogadro's law states that the number of moles of gas and volume of a gas is directly proportional. A plot of $n$ vs. $V$ is required.
Work Step by Step
Inverse proportionality means that when one value increases, the other decreases by the same proportion. Conversely, direct proportionality means that when one value increases, the other increases by the same proportion. Therefore, direct proportionality is already in a linear relationship. However, inverse proportionality is linear when one of the values is converted to its reciprocal.