1. ANATOMY OF A Z-SCORE z-score -3 -2 -1 1 2 3
A z-score is a measure of distance from a standardized value to the mean of the Standard Normal Distribution, a special distribution with a mean equal to 0, and a standard deviation equal to 1.
The units marked on the horizontal axis of the Standard Normal Distribution are called Z-Scores (or Z-Values). A specific value of z gives the distance between the mean and the point represented by z, in terms of the standard deviation.
A z-score of -2
corresponds to the point that is two
standard deviations to the left of
A z-score of 3
corresponds to the point that is
three standard deviations to the right of
z-score -3 -2 -1 1 2 3
REMEMBER… a z-score can be negative (to the left of the mean), or
positive (to the right of the mean). Areas/probabilities are NEVER negative.