[[Actuarial Notes Wiki|Wiki]] / [[Actuarial Math]] / ==Probability Theory== > **Probability theory** is a branch of mathematics and statistics concerning events and numerical descriptions of how likely they are to occur. > > Probability theory is used to >- Quantify uncertainty >- Predict the likelihood of outcomes of an experiment > The [[probability]] of an event is a number between 0 and 1, where larger probabilities means an event is more likely to occur. > Uncertainty about random phenomena is represented as a [[Concepts/Probability Distributions|probability distribution]] which assigns probabilities to all possible outcomes of an experiment.