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The Wilcoxon signed-rank test is a non-parametric rank test for statistical hypothesis testing used either to test the location of a population based on a sample of data, or to compare the locations of two populations using two matched samples. [1] The one-sample version serves a purpose similar to that of the one-sample Student's t-test. [2]
Dunnett's test's calculation is a procedure that is based on calculating confidence statements about the true or the expected values of the differences ¯ ¯, thus the differences between treatment groups' mean and control group's mean.
The simplest version of the test statistic from this auxiliary regression is TR 2, where T is the sample size and R 2 is the coefficient of determination. Under the null hypothesis of no autocorrelation, this statistic is asymptotically distributed as χ 2 {\displaystyle \chi ^{2}} with k degrees of freedom.
The bias-corrected and accelerated ... but with a different formula (note the inversion of the left and right quantiles): ... for a sample size n; this ...
Conversely, a “large" R 2 (scaled by the sample size so that it follows the chi-squared distribution) counts against the hypothesis of homoskedasticity. An alternative to the White test is the Breusch–Pagan test, where the Breusch-Pagan test is designed to detect only linear forms of heteroskedasticity. Under certain conditions and a ...
In equations, the typical symbol for degrees of freedom is ν (lowercase Greek letter nu).In text and tables, the abbreviation "d.f." is commonly used. R. A. Fisher used n to symbolize degrees of freedom but modern usage typically reserves n for sample size.
In Petrophysics a Klinkenberg correction is a procedure for calibration of permeability data obtained from a minipermeameter device. A more accurate correction factor can be obtained using Knudsen correction .
where ¯ is the sample mean, s is the sample standard deviation, m 2 is the (biased) sample second central moment, and m 3 is the (biased) sample third central moment. [6] is a method of moments estimator. Another common definition of the sample skewness is [6] [7]