F-TEST
F -test An F -test is any statistical test in which the test statistic has an F -distribution under the null hypothesis . It is most often used when comparing statistical models that have been fitted to a data set, in order to identify the model that best fits the population from which the data were sampled. Exact " F -tests" mainly arise when the models have been fitted to the data using least squares . The name was coined by George W. Snedecor , in honour of Ronald Fisher . Fisher initially developed the statistic as the variance ratio in the 1920s. [1] Common examples [ edit ] Common examples of the use of F -tests include the study of the following cases: The hypothesis that the means of a given set of normally distributed populations, all having the same standard deviation , are equal. This is perhaps the best-known F -test, an...