We need to determine the relation between volumes \( V_1, V_2, V_3, V_4 \) from a \( P \) vs. \( T \) graph of an ideal gas.
Step 1: Use the ideal gas law.
For an ideal gas: \( PV = nRT \). Rewriting:
\[
P = \left( \frac{nR}{V} \right) T
\]
In a \( P \) vs. \( T \) graph, each line has a slope of \( \frac{nR}{V} \), which is inversely proportional to \( V \).
Step 2: Analyze the slopes.
The graph shows \( V_1 \) has the largest slope, and \( V_4 \) the smallest. Since slope \( \propto \frac{1}{V} \):
\[
\frac{1}{V_1}>\frac{1}{V_2}>\frac{1}{V_3}>\frac{1}{V_4} \implies V_1<V_2<V_3<V_4
\]
Final Answer:
\[
\boxed{V_1<V_2<V_3<V_4}
\]