The chi square distribution is a probability density function used in statistics to determine the probability that numerical differences in data are significant and real (as opposed to just being due to random errors or chance). Chi is a Greek letter...

A chi-square model is a statistical method used to analyze the results of certain types of experiments. It involves a comparison of the deviation of real observations from expected values, and helps determine whether a result is significant or not. It...

The distribution of chi-squared statistics where chi is the sum of the squares of the deviations of observations from their sample mean divided by the square of the standard deviation of the population from which the sample is taken. There are...

(χ2) A statistical test to determine how closely an observed set of data values corresponds to the values expected, under a specific...

cdf =\frac{\gamma(k/2,x/2)}{\Gamma(k/2)}\,| mean =k\,| median =approximately k-2/3\,| mode =k-2\, if k\geq 2\,| variance...

The null hypothesis that the proportions or relative abundance among j mutually exclusive categories (e.g., species or sizes) is the same for two or more populations (e.g., locations or sexes, respectively) is often tested with the Pearson chi-square goodness-of-fit statistic. The chi-square statistic is...

Results from the theory of linear models establish a particular idempotency condition as being necessary and sufficient for a quadratic form in a nonsingular normal vector to follow a chi-square distribution. We give a theorem that is somewhat stronger than the standard ones,...