Chebyshev's inequality
/ (ˈtʃɛbɪˌʃɒfs) /
noun
statistics
the fundamental theorem that the probability that a random variable differs from its mean by more than k standard deviations is less than or equal to 1/ k ²
Word Origin for Chebyshev's inequality
named after P. L.
Chebyshev (1821–94), Russian mathematician