# Definition:Probability Theory

## Definition

**Probability theory** is the branch of mathematics which studies probability spaces.

## Also see

- Results about
**probability theory**can be found**here**.

## Historical Note

The discipline of **probability theory** is suggested by some sources to be a creation shared between Pierre de Fermat and Blaise Pascal.

Their intent was to describe certain games of chance and to calculate various probabilities.

They developed the fundamental principles in a series of letters in the year $1654$.

The field was developed significantly by Jacob Bernoulli, the results of his research appearing in his posthumous *Ars Conjectandi* of $1713$.

Modern probability theory is more than just calculating the chance of getting $m$ heads while tossing $n$ coins.

It is used to study problems in fields as diverse as economics, genetics, sociology, astronomy and physics.

## Sources

- 1972: Murray R. Spiegel and R.W. Boxer:
*Theory and Problems of Statistics*(SI ed.) ... (previous) ... (next): Chapter $1$: Variables and Graphs: Population and Sample. Descriptive and Inductive Statistics - 1977: Gary Chartrand:
*Introductory Graph Theory*... (previous) ... (next): $\S 4.2$: Trees and Probability - 1986: Geoffrey Grimmett and Dominic Welsh:
*Probability: An Introduction*... (previous) ... (next): $1$: Events and probabilities: $1.1$: Experiments with chance