﻿

# 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.

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.

Investment dictionary. . 2012.

### Look at other dictionaries:

• Chi-square test — is often shorthand for Pearson s chi square test. A chi square test (also chi squared or chi^2 test) is any statistical hypothesis test in which the test statistic has a chi square distribution when the null hypothesis is true, or any in which… …   Wikipedia

• chi-square test — any statistical hypothesis test that employs the chi square (χ2) distribution (q.v.), especially two tests applied to categorical data: the χ2 test of goodness of fit, which tests whether an observed frequency distribution fits a… …   Medical dictionary

• chi-square test — noun any statistical hypothesis test in which the test statistic has a chi square distribution if the null hypothesis is true …   Wiktionary

• chi-square — noun A test statistic used in the chi square test …   Wiktionary

• chi-square — noun Usage: often attributive Date: 1900 a statistic that is a sum of terms each of which is a quotient obtained by dividing the square of the difference between the observed and theoretical values of a quantity by the theoretical value …   New Collegiate Dictionary

• Pearson's chi-square test — Pearson s chi square ( chi;2) test is the best known of several chi square tests – statistical procedures whose results are evaluated by reference to the chi square distribution. Its properties were first investigated by Karl Pearson. In contexts …   Wikipedia

• chi-squaretest — chi square test n. A test that uses the chi square statistic to test the fit between a theoretical frequency distribution and a frequency distribution of observed data for which each observation may fall into one of several classes. * * * …   Universalium

• Statistic — A statistic (singular) is the result of applying a function (statistical algorithm) to a set of data. More formally, statistical theory defines a statistic as a function of a sample where the function itself is independent of the sample s… …   Wikipedia

• Chi-squared test — Chi square test is often shorthand for Pearson s chi square test. A chi square test, also referred to as chi squared test or χ2 test, is any statistical hypothesis test in which the sampling distribution of the test statistic is a chi square… …   Wikipedia

• Chi-squared distribution — This article is about the mathematics of the chi squared distribution. For its uses in statistics, see chi squared test. For the music group, see Chi2 (band). Probability density function Cumulative distribution function …   Wikipedia