Function - Probability Chebyshev Inequality

function to calculate Chebyshev Inequality. wich can be used to compute the probability that we will diverge from what we expect to obtain.

reference:
- omnicalculator.com/statistics/chebyshevs-theorem
- github.com/antoniocruces/microsites/blob/638a6170d73065de6fcf026ff513e8814afc3196/assets/scripts/services/StatsHelpers.js
- statisticstopics.wordpress.com/2017/12/16/chebyshevs-inequality/
- en.wikipedia.org/wiki/Chebyshev's_inequality