What can be deduced from the shape of this graph?

The graph shows a plot of Volume ($V$) against the reciprocal of Pressure ($1/P$). The data points form a straight line that passes through the origin.

A straight line passing through the origin on a graph of $y$ versus $x$ indicates that $y$ is directly proportional to $x$. In this case, $V$ is directly proportional to $1/P$.

The direct proportionality between volume and the reciprocal of pressure ($V \propto \frac{1}{P}$), or equivalently, that the product of pressure and volume is constant ($PV = \text{constant}$), is known as Boyle's Law. This law applies to a fixed mass of gas at a constant temperature.

From the shape of this graph, it can be deduced that:
The volume of the gas is directly proportional to the reciprocal of its pressure, which is consistent with Boyle's Law.