What does a bounded ratio of regional mass means tell us?

[stvoffutt]

I was looking at a research paper the other day. In the paper they described some of the results from an experiment. They looked at two of the variables recorded in the experiment, mass and velocity. They looked at mass independently. First, they took the median of the mass. They then had two regions for mass in which they calculated the means of these two regions and looked at the ratio of the means of the regions w.r.t. the mean of the whole mass. This ratio was bounded for several experiments.

I was wondering what this statistic meant. Where does it come from and what does it tell us?

 

[RUber]

It sounds like they were trying to describe some sort of variability in the mass distribution.
You mentioned that the ratio was bounded, so perhaps they were building a baseline to use in lieu of the actual mass distribution and variance.
Did they use these values anywhere else in the paper?