Ok I know that the probability of a Z-score of 4 is .49997. I simply want to find out HOW this number was calculated from a Z-score chart that only goes up to like 3.49.

Z-score charts typically only go up to 3.4 and 3.49, so how do I find the probability of a Z-score equaling 4?

*NOTE* this is finite math. please be descriptive as possible and refrain from statistics and calculus solutions.

much thanks!