Answer
The higher the molar mass/the easier polarizable a gas atom is, the more soluble it will be.
Work Step by Step
Gases with a higher molar mass are more polarizable and therefore have more dispersion forces. These dispersion forces cause the gases to be more soluble. This is evident with Xe and it has a higher molar mass and polarizability than both Ar and Kr and is, as a result, more soluble.
