Thread: when is the empricial rule true?

Does the empirical rule (aka 68-95-99.7 rule) only apply to normal distribution or is it true for skewed data as well?

My guess is yes, because the standard deviation is differnt between normally distributed data and skewed data.

Originally Posted by superdude

Does the empirical rule (aka 68-95-99.7 rule) only apply to normal distribution or is it true for skewed data as well?

My guess is yes, because the standard deviation is differnt between normally distributed data and skewed data.

These are the probabilities of being within 1, 2 and 3 SD's of the mean for a normally distributed random variable. They do not apply in general.

CB