measure of dispersion centered around a mean. two types  1) continuous: generally steady progression and  2) discrete: attributes are separate from one another
measure of dispersion centered around a mean. two types  1) continuous: generally steady progression and  2) discrete: attributes are separate from one another
a summarization of values around the mean. within a normal distribution, approximately 68% and 95% fall within + or - 1 or 2 standard deviation points respectively.