If the numerical values assumed by a variable are the result of some chance factors, so
that a particular value cannot be exactly predicted in advance, the variable is then called a
random variable. A random variable is also called â€˜chance variableâ€™ or â€˜stochastic variableâ€™.
Random variables are denoted by capital letters, usually, from the last part of the
alphabet, for instance, X, Y, Z etc.