Category:Definitions/Probability

This category contains definitions related to Probability.
Related results can be found in Category:Probability.

Informal Definition

The probability of an event is the likelihood that the event will occur (within a certain formally or informally understood context).

As such, a probability can range from $0$ (will never happen) to $1$ (is certain to happen).

Commonly, a probability is often stated in terms of a percentage.

Formal Definition

Let $\EE$ be an experiment.

Let $A \in \Sigma$ be an event in the event space $\Sigma$ of $\EE$.

Let $\Pr$ be the probability measure of $\EE$.

Then the probability of $A$ is the value $\map \Pr A$.