"If you don't know the number, and have no way of getting the number, then you can't use it to make a decision." Ya see, it's this kinda statement that puzzles me. You are in effect sayin, it seems, that if you don't know, then the information is irrelevant and/or that if you "don't know," then all decisions are equal in consequence, and should therefore be selected from merely on the basis of what one "feels" like deciding.
Certainly, not all decisions are equal in consequence. That doesn't mean the actual number is relevant to the decision. What becomes relevant are other factors. If I trust the person asking me to jump or have some way of knowing that my jump will effect some significant effect, I'll jump whether the distance is ten inches or ten stories, because I don't know the difference between ten inches or ten stories, I just know I trust the person or want the effect. If I don't trust the person and have no good reason to jump, I won't jump, whether the distance is ten inches or ten stories. So, again, what is the pragmatic significance concerning the decision to jump (as opposed to the consequences afterward)?