ABSTRACT
The most common way to model a continuous random variable is by means of a curve called a probability density function (pdf) or simply a density. A probability density function f (x) is a real valued function having two basic properties:
(i) f (x)≥ 0 for all x ∈ (-∞, ∞ ), (ii) ∫ ∞ −∞ f (x)dx = 1.
