chi-square distribution

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Related to Chi-squared distribution: T distribution, Beta distribution

chi-square dis·tri·bu·tion

a variable is said to have a chi-square distribution with K degrees of freedom if it is distributed like the sum of the squares of K independent random variables, each of which has a normal (gaussian) distribution with mean zero and variance one. The chi-square distribution is the basis for many variations of the chi-square(d) test, perhaps the most widely used test for statistical significance in biology and medicine.

chi-square distribution

in statistical terms this is said of a variable with K degrees of freedom if it is distributed like the sum of the squares of K independent random variables each of which has a normal distribution with mean zero and variance of 1.
References in periodicals archive ?
anomala, step lengths appeared to have a finite distribution well approximated by a chi-squared distribution (Fig.
0]), PINTO (2009) reported that the LRT approximated by the chi-squared distribution does not control type I errors for samples of size n=10 in bivariate situations and for samples of sizes n=10 and 25 in situations with P=3 and 5 variables.
3) Furthermore, this result helps us to reconcile the form of the asymptotic approximation proposed in Theorem 1 with the weighted chi-squared distribution that arises in some special cases as in Example 2 above.
048 Table 12 P-values from Pair-wise T-tests on Means of MAD's from MA(1), MA(3), MA(5), MA(7), MA (9) for the Chi-squared Distribution with c.
p] had a chi-squared distribution with 2 degrees of freedom corrected (Bonferroni correction) for 4.
We present a simple new function, the cumulative chi-squared distribution, for assessing regions of misfit in a diffraction pattern and introduce a matrix which relates the impact of individual points in a powder diffraction pattern with improvements in the estimated standard deviation of refined parameters.
This deflation factor is then applied to the observed G statistic, which is then compared with the chi-squared distribution to calculate the final P value.
Denoting the ratio of the restricted value to the unrestricted value as [lambda], the test relies on the fact that -2ln[lambda] follows a chi-squared distribution.