A random or statistical experiment is one in which
(i) All possible outcomes of the experiment are known in advance.
(ii) A performance of an experiment results in an outcome that is not known in advance.
(iii) The experiment can be repeated under identical conditions.
A random variable is a quality resulting from a random experiment that, by chance, can assume different values.
→ A discrete random variable may assume either a finite number of values or an infinite sequence of values.
→ A Continuous random Variable may assume any numerical value in an interval or collections of intervals.