Ok so basically the chebyshev's theorem states that 75% of your data will lie within 2 standard deviations of the mean and that 89% of your data will lie within 3 standard deviations
http://wiki.answers.com/Q/What_is_Chebyshev's_theo...

For any positive constant 'k' the probability that a random variable will take on a
http://www.chacha.com/question/whatisthechebysh...

For number k greater than 1, at least 11/k2 of data will fall within k standard deviations of mean.
http://www.kgbanswers.com/whatistheequationof...
