chi-square distribution

• chi-squared distribution
• χ² distribution

chi-square distribution (plural chi-square distributions)

1. (statistics) A probability distribution widely used in inferential statistics.
   • 1992, Harold R. Lindman, Analysis of Variance in Experimental Design, Springer, Softcover Reprint, page 7,

     The chi-square distribution with ${\displaystyle \nu }$ degrees of freedom is defined to be the distribution of the sum of ${\displaystyle \nu }$ independent squared random variables, each having the standard normal distribution.

   • 2003, Chin Long Chiang, Statistical Methods of Analysis, World Scientific Publishing, page 204,

     The family of chi-square distributions, like the "Student's" t distributions, has an infinite number of members, one for each number of degrees of freedom.

   • 2012, Anthony J. Hayter, Probability and Statistics for Engineers and Scientists, 4th Edition, Cengage Learning, page 254,

     The degrees of freedom of a chi-square distribution are usually denoted by the Greek letter ${\displaystyle \nu }$ and can take any positive integer value.

The synonym central chi-square distribution is sometimes used in distinction with the more general noncentral chi-square distribution.

• (probability distribution): central chi-square distribution

• chi-square test

• chi distribution