Changes

'''Probability''' theory is the study of uncertainty, a relatively modern field

'''Probability''' theory is the study of uncertainty, a relatively new branch of mathematics.

The '''probability''' of an event is a number between 0 and 1 representing the likelihood of the event's occurrence.  It may be expressed as a simple fraction, decimal fraction, or percentage. When there are a finite number of equally likely outcomes, the probability of an event is given by

The '''probability''' of an event is a number between 0 and 1 representing the likelihood of the event's occurrence.  It may be expressed as a simple fraction, decimal fraction, or percentage. When there are a finite number of equally likely outcomes, the probability of an event is given by