Simple question to which I can't find the answer. Does Steady Hand increase success additively, or multiplicatively? To put it another way, does Hasty Touch become a 70% success rate skill, or a 60% success rate skill, when under Steady Hand?

The obvious test for this is using Standard Touch, which would generate either a 100% or 96% rate, but that one would take a while for me to test to a reasonable degree of certainty. This is much faster.