Solution:
At lower pressure, the graph is nearly straight and sloping, i.e.,
$$
\begin{aligned}
&\frac{x}{m} \propto p^{1} \\
&\text { or } \frac{x}{m}=\text { constant } \times p^{1}
\end{aligned}
$$
At high pressure, \(\frac{x}{m}\) becomes independent of value of pressure.
$$
\begin{aligned}
&\frac{x}{m} \propto p^{0} \\
&\text { or } \frac{x}{m}=\text { constant }
\end{aligned}
$$
In the intermediate range of pressure, \(\frac{x}{m}\) will depend on \(p\) raised to powers between 1 and 0 , i.e., fractions.
$$
\begin{aligned}
&\frac{x}{m} \propto p^{\frac{1}{n}} \\
&\text { or } \frac{x}{m}=\text { constant } \times p^{\frac{1}{n}}
\end{aligned}
$$
