1.065 x 1.15 = 1.22475.
That statement is mathematically correct.
But in the context, it makes no sense.
I have heard other people state like fact that "in mmo/rpg, this is how multipliers are added."
What u have here, mathematically, is 106.5% chance to evade x 115% = 122.5% chance to evade. That is nonsense.
You do not arbitrarily add 100% to the base dodge rate before doing the multiplication, then subtract it, after. The confusion may come from the 115%. In this case you do it because the 15% is an increase from 100% of the baseline rate. You do not add the 100% then mutiply, then subtract it. After multiplying, you are done. It is not arbitrarily added then removed.
Not all mmo rpg experts paid atten5ion in high school. It may indeed be the way Runescape works, or whatnot. But that doesn't make any mathematical sense. In fact, what you are doing here is straight adding +15% and then adding an additional 15% of base on top of that. There is no (competent) mathematician in the world that will tell you this equates to increasing the base rate by 15%, anyway you color it.