Definition of chi–square distribution
: a probability density function that gives the distribution of the sum of the squares of a number of independent random variables each with a normal distribution with zero mean and unit variance, that has the property that the sum of two or more random variables with such a distribution also has one, and that is widely used in testing statistical hypotheses especially about the theoretical and observed values of a quantity and about population variances and standard deviations
First Known Use of chi–square distribution
Seen and Heard
What made you want to look up chi–square distribution? Please tell us where you read or heard it (including the quote, if possible).