**Probability** is a measure of the expectation that an event will occur or a statement is true. Probabilities are given a value between 0 (will not occur) and 1 (will occur). The higher the probability of an event, the more certain we are that the event will occur.

The concept has been given an axiomatic mathematical derivation in probability theory, which is used widely in such areas of study as mathematics, statistics, finance, gambling, science, artificial intelligence/machine learning and philosophy to, for example, draw inferences about the expected frequency of events. Probability theory is also used to describe the underlying mechanics and regularities of complex systems.

Read more about Probability: Interpretations, Etymology, History, Theory, Applications, Mathematical Treatment, Relation To Randomness

### Famous quotes containing the word probability:

“Legends of prediction are common throughout the whole Household of Man. Gods speak, spirits speak, computers speak. Oracular ambiguity or statistical *probability* provides loopholes, and discrepancies are expunged by Faith.”

—Ursula K. Le Guin (b. 1929)

“Crushed to earth and rising again is an author’s gymnastic. Once he fails to struggle to his feet and grab his pen, he will contemplate a fact he should never permit himself to face: that in all *probability* books have been written, are being written, will be written, better than anything he has done, is doing, or will do.”

—Fannie Hurst (1889–1968)

“The source of Pyrrhonism comes from failing to distinguish between a demonstration, a proof and a *probability*. A demonstration supposes that the contradictory idea is impossible; a proof of fact is where all the reasons lead to belief, without there being any pretext for doubt; a *probability* is where the reasons for belief are stronger than those for doubting.”

—Andrew Michael Ramsay (1686–1743)