The empirical rule states if an distribution is symmetrical and bell-shaped, approximately _______, 95%, and 99.7% of its data values will fall within one, two, and three standard deviations above and below the mean, respectively.
In Statistics, application of the empirical rule can be applied to the empirical formula for calculating the mean and standard deviation of values given. In normal "symmetrical" and bell-shaped distribution, approximately 68% of values fall within one standard deviation above and below the mean. 68% of values fall => m ± 1 sd 95% of values fall => m ± 2sd 99.7% values fall => m ± 3sd
