Khan/khan-exercises — pull request #14252 by smenks13 (2012-02-20 22:26:31+00:00)
Title: New exercise: Z-scores 1

@beneater

An exercise demonstrating areas under the normal distribution. It actually doesn't go into what a z-score is at all, but I think it could act as a precursor to a follow-up exercise, where the user is asked to find the probability that a variable is within a certain range by first calculating the z-scores, and then manipulating the graph of the standard normal distribution to find the area.

Also, I entered a z-table by hand. Go me.