Statistical Methods

Unit 2 - Probability distributions

2.2.Random variable
Random variable is a real number ‘x’ assigned for outcome of a random experiment. Consider an experiment of tossing of a coin twice. Then the experiment has the outcomes HH, HT, TH and TT where H and T refer to head and tail respectively. If the number of heads is considered as a random variable X, then its value corresponding to different outcomes is as follows:

Thus random variable is a function that assigns a real number to each outcome in a sample space of a random experiment.