ABSTRACT
In most engineering experiments, the outcomes appear in a random and on deterministic fashion. The operating time of a system before failure, the tensile strength of a certain type of material, and the number of defective items in a batch of items produced are all subject to random variations from one experiment to another. A random variable takes a numerical value that depends on the outcome of the experiment. Since the outcome of an experiment is subject to random variation, the resulting numerical value is also random. In order to provide a stochastic model for describing the probability distribution of a random variable, the random variables are classified into two groups: the discrete type and the continuous type. The discrete random variables are those which take a finite number or a countably infinite number of possible numerical values.
