Chebyshev's inequality - Wikipedia
https://en.wikipedia.org/wiki/Chebyshev's_inequalityIn probability theory, Chebyshev's inequality (also called the Bienaymé–Chebyshev inequality) guarantees that, for a wide class of probability distributions, no more than a certain fraction of values can be more than a certain distance from the mean. Specifically, no more than 1/k of the distribution's values can be k or more standard deviationsaway from the mean (or equivalently, over 1 − 1/k of the distribution's values are less than k standard deviations away from the mean)…
Chebyshev’s & Empirical rules - Sacramento State
www.csus.edu › s › seriaChebyshev’s & Empirical rules . Chebyshev’s rule. For any data set, the proportion (or percentage) of values that fall within k standard deviations from mean [ that is, in the interval () ] is at least () , where k > 1 . Empirical rule. For a data set with a symmetric distribution , approximately 68.3 percent of the values will fall within one standard deviation from the mean, approximately 95.4 percent will fall within 2 standard deviations from the mean, and approximately 99.7 percent ...