DEFINITION of 'Joint Probability'
A statistical measure where the likelihood of two events occurring together and at the same point in time are calculated. Joint probability is the probability of event Y occurring at the same time event X occurs.
Notation for joint probability takes the form:
INVESTOPEDIA EXPLAINS 'Joint Probability'
Joint probability is a measure of two events happening at the same time, and can only be applied to situations where more than one observation can be occurred at the same time.
For example, a joint probability can not be calculated when tossing a coin on the same flip. However, the joint probability can be calculated on the probability of rolling a 2 and a 5 using two different dice.
RELATED TERMS

Conditional Probability
Probability of an event or outcome based on the occurrence of ... 
Statistics
A type of mathematical analysis involving the use of quantified ... 
Probability Distribution
A statistical function that describes all the possible values ... 
NonSampling Error
A statistical error caused by human error to which a specific ... 
Sampling Error
A statistical error to which an analyst exposes a model simply ... 
Compound Annual Growth Rate  CAGR
The yearoveryear growth rate of an investment over a specified ...
Related Articles

Fundamental Analysis
Find The Right Fit With Probability Distributions
Discover a few of the most popular probability distributions and how to calculate them. 
Active Trading Fundamentals
Bet Smarter With The Monte Carlo Simulation
This technique can reduce uncertainty in estimating future outcomes. 
Options & Futures
An Introduction To Value at Risk (VAR)
Volatility is not the only way to measure risk. Learn about the "new science of risk management". 
Active Trading Fundamentals
How To Convert Value At Risk To Different Time Periods
Volatility is not the only way to measure risk. Learn about the "new science of risk management". 
Personal Finance
What is the average salary for an accountant?
Learn about the average salaries of various accounting positions, and see the difference that an accounting degree makes in attaining higher wages. 
Fundamental Analysis
Lognormal and Normal Distribution
When and why do you use lognormal distribution or normal distribution for analyzing securities? Lognormal for stocks, normal for portfolio returns. 
Economics
Where is cost of living lowest in the world?
Learn how the cost of living is the lowest in India based on numbers derived from the CPI and organizations like Expatistan and Numbeo. 
Economics
Is the Bureau of Labor Statistics accurate?
Read this brief analysis of the accuracy of Bureau of Labor Statistics, including a summary of the types of reports issued and how they are compiled. 
Investing Basics
Using Normal Distribution Formula To Optimize Your Portfolio
Normal or bell curve distribution can be used in portfolio theory to help portfolio managers maximize return and minimize risk. 
Economics
How does the Bureau of Labor Statistics define contingent workers?
Discover how contingent workers are a significant part of the labor force and are defined as persons who do not expect their jobs to last.