I still see you posting inaccurate math information. It's good to know you continue to post about things you don't really know. If you did indeed take a math class, you didn't take enough from it.
Let me ask you this. If you had a spell that did 50-100 damage, and you had an enhancement that did 200% increase in damage... how many times would you have to cast it to find out if it worked?
The answer is not 1000, or 2000, or 3000 with however % of certainty.
The answer is once.
If you don't see why that is, then you're not understanding the problem. If normal magic missile can only do 4-5 damage, then you can quickly tell if something is modifying them with such little variance.