Probability is a measure of the likeliness that an event will occur. Probability is used to quantify an attitude of mind towards some proposition whose truth is not certain. The proposition of interest is usually of the form "A specific event will occur." The attitude of mind is of the form "How certain is it that the event will occur?" The certainty that is adopted can be described in terms of a numerical measure, and this number, between 0 and 1 (where 0 indicates impossibility and 1 indicates certainty) is called the probability. Probability theory is used extensively in statistics, mathematics, science and philosophy to draw conclusions about the likelihood of potential events and the underlying mechanics of complex systems.

Introduction

Probability and randomness.

Outline of probability

Basic probability

(Related topics: set theory, simple theorems in the algebra of sets)

Outline of probability

Events

Events in probability theory

Elementary events, sample spaces, Venn diagrams

Mutual exclusivity

Elementary probability

The axioms of probability

Boole's inequality

Meaning of probability

Probability interpretations

Bayesian probability

Frequency probability

Calculating with probabilities

Conditional probability

The law of total probability

Bayes' theorem

Independence

Independence (probability theory)

Outline of probability

Probability theory

(Related topics: measure theory)

Measure-theoretic probability

Sample spaces, σ-algebras and probability measures

Probability space

Sample space

Standard probability space

Random element

Random compact set

Dynkin system

Probability axioms

Event (probability theory) Complementary event Elementary event "Almost surely"

Independence

Independence (probability theory) The Borel–Cantelli lemmas and Kolmogorov's zero–one law

Conditional probability

Conditional probability

Conditioning (probability) Conditional expectation Conditional probability distribution Regular conditional probability Disintegration theorem Bayes' theorem Rule of succession Conditional independence Conditional event algebra Goodman–Nguyen–van Fraassen algebra

Random variables

Discrete and continuous random variables

Discrete random variables: Probability mass functions

Continuous random variables: Probability density functions

Normalizing constants

Cumulative distribution functions

Joint, marginal and conditional distributions

Expectation

Expectation (or mean), variance and covariance

Jensen's inequality

General moments about the mean

Correlated and uncorrelated random variables

Conditional expectation: law of total expectation, law of total variance Fatou's lemma and the monotone and dominated convergence theorems Markov's inequality and Chebyshev's inequality

Independence

Independent random variables

Some common distributions

Discrete: constant (see also degenerate distribution), Bernoulli and binomial, negative binomial, (discrete) uniform, geometric, Poisson, and hypergeometric. Continuous: (continuous) uniform, exponential, gamma, beta, normal (or Gaussian) and multivariate normal, χ-squared (or chi-squared), F-distribution, Student's t-distribution, and Cauchy.

Some other distributions

Cantor

Fisher–Tippett (or Gumbel) Pareto Benford's law

Functions of random variables

Sum of normally distributed random variables

Borel's paradox

Generating functions

(Related topics: integral transforms)

Common generating functions

Probability-generating functions

Moment-generating functions

Laplace transforms and Laplace–Stieltjes transforms

Characteristic functions

Applications

A proof of the central limit theorem

Convergence of random variables

(Related topics: convergence)

Modes of convergence

Convergence in distribution and convergence in probability, Convergence in mean, mean square and rth mean Almost sure convergence Skorokhod's representation theorem