DEFINITION of 'Chi Square Statistic'
A measurement of how expectations compare to results. The data used in calculating a chi square statistic must be random, raw, mutually exclusive, drawn from independent variables and be drawn from a large enough sample. For example, the results of tossing a coin 100 times would meet these criteria.
INVESTOPEDIA EXPLAINS 'Chi Square Statistic'
As a simple example of how to calculate and use the chi square statistic, consider tossing a coin 100 times. The expected result of tossing a fair coin 100 times is that heads will come up 50 times and tails will come up 50 times. The actual result might be that heads comes up 45 times and tails comes up 55 times. The chi square statistic will show any discrepancies between the expected results and the actual results.
RELATED TERMS

GoodnessOfFit
Used in statistics and statistical modelling to compare an anticipated ... 
Nonparametric Statistics
A statistical method wherein the data is not required to fit ... 
Sampling Error
A statistical error to which an analyst exposes a model simply ... 
Descriptive Statistics
A set of brief descriptive coefficients that summarizes a given ... 
Statistics
A type of mathematical analysis involving the use of quantified ... 
Multiple Linear Regression  MLR
A statistical technique that uses several explanatory variables ...
Related Articles

Investing Basics
What Are The Odds Of Scoring A Winning Trade?
Just because you're on a winning streak doesn't mean you're a skilled trader. Find out why. 
Investing Basics
Regression Basics For Business Analysis
This tool is easy to use and can provide valuable information on financial analysis and forecasting. Find out how. 
Active Trading
The Linear Regression Of Time and Price
This investment strategy can help investors be successful by identifying price trends while eliminating human bias. 
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. 
Economics
How does the Bureau of Labor Statistics determine the Consumer Price Index (CPI)?
Changes in the average price level of more than 200 goods and services across the U.S. economy are used to determine the Consumer Price Index, or CPI.