Definition

The chance or likelihood of an event occurring. It is often expressed as the relative frequency of the event, written as the ratio of the number of actual occurrences to the number of possible occurrences. Probabilities take values between zero and 1, with zero representing an impossible event and 1 representing a certain event. Most probabilities fall somewhere in between.

Examples

1. Of the last five times you went to a particular restaurant, three of those times you had to wait in line to be seated. The probability of having to wait to be seated at this restaurant = 3/5.

2. There are 5 booths and 10 tables at the restaurant. The probability that you will be seated at a booth = 5/15.