nStandardizes your data
distribution

nConvert raw scores into z-scores

nIf X = 10, SD = 2, X = 11.7

z = __ 11.7 - 10 __ = __1.7__ = .85

2
2

nUse z Table to find area under
bell curve

n1st column is z-score

n2nd column is proportion between
mean and z

n3rd column is proportion in the
tail beyond z