Let be a real-valued random variable with mean and variance . Then for any standard of accuracy ,
Note: There is another Chebyshev's inequality, which is unrelated.
![$ \mu=\mathbb{E}[X]$](http://images.planetmath.org:8080/cache/objects/3115/l2h/img2.png "$ \mu=\mathbb{E}[X]$"){kind=small}
![$ \sigma^2=\operatorname{Var} [X]$](http://images.planetmath.org:8080/cache/objects/3115/l2h/img3.png "$ \sigma^2=\operatorname{Var} [X]$"){kind=small}
