The story
From the surname of Russian mathematician Pafnuty Chebyshev (1821–1894), the discoverer.
Etymology from Wiktionary, CC BY-SA 4.0.
Chebyshev's inequality
Today it means: The theorem that in any data sample with finite variance, the probability of any random variable X that lies k or more standard deviations away from the mean is no more than 1/k², i.e. assuming mean μ and standard deviation σ, the probability is Full definition →