Conclusion
The data seems to support the hypothesis that the range and velocity of the projectile are proportional to the square root of the mass of the counterweight, as shown by the nature of the Mass-Range and Mass-Velocity functions. There is enough inconsistency in the data, though, to make it possible that the relationship is not a square root function but a linear or possibly parabolic one. While there was insufficient data to show an inverse relationship between arm length, range, and velocity, by comparing the Mass-Range and Mass-Velocity graphs of different arm lengths, we can infer the inverse relationship.
The efficiency of the trebuchet was shown to be related to mass and arm length in the same way as velocity and range. As to how this ranks other trebuchets, it is possible that the fixed weight trebuchet would have half the efficiency, while putting wheels on either would perhaps triple the efficiency. These are at best educated guesses, though. A Floating-Arm Trebuchet could possibly have upwards of fifty-percent efficiency, however, as the largest energy well on the other types of trebuchets, that of the counterweight, is significantly reduced as the counterweight on a Floating-Arm Trebuchet actually stops during the firing of the projectile.
There are now new ideas to be tested. How would the data look if there were enough trials of different arm lengths? How much energy is still in the counterweight after the firing of the projectile? Why does the efficiency of the trebuchet vary with mass and arm length? Exactly what is the efficiency of the other types of trebuchets? How does the efficiency of the trebuchet compare with the efficiency of other medieval siege weapons? Now that the trebuchet has been built, it is time to find out everything about it.