https://manuals.pqstat.pl/ 2026-04-30T22:24:22+00:00 https://manuals.pqstat.pl/ https://manuals.pqstat.pl/lib/tpl/dokuwiki/images/favicon.ico text/html 2022-02-11T20:19:58+00:00 Anonymous (anonymous@undisclosed.example.com) https://manuals.pqstat.pl/en:statpqpl:porown2grpl:parpl:snedecpl The Fisher-Snedecor test The F-Snedecor test is based on a variable which was formulated by Fisher (1924), and its distribution was described by Snedecor. This test is used to verify the hypothesis about equality of variances of an analysed variable for 2 populations. text/html 2022-09-13T21:51:33+00:00 Anonymous (anonymous@undisclosed.example.com) https://manuals.pqstat.pl/en:statpqpl:porown2grpl:parpl:t_test2niezalcpl The t-test for independent groups The -test for independent groups is used to verify the hypothesis about the equality of means of an analysed variable in 2 populations. Basic assumptions: * measurement on an interval scale, * normality of distribution of an analysed feature in both populations, text/html 2022-09-13T22:34:58+00:00 Anonymous (anonymous@undisclosed.example.com) https://manuals.pqstat.pl/en:statpqpl:porown2grpl:parpl:t_test2zalcpl The t-test for dependent groups The -test for dependent groups is used when the measurement of an analysed variable you do twice, each time in different conditions (but you should assume, that variances of the variable in both measurements are pretty close to each other). We want to check how big is the difference between the pairs of measurements ( text/html 2022-02-11T20:38:15+00:00 Anonymous (anonymous@undisclosed.example.com) https://manuals.pqstat.pl/en:statpqpl:porown2grpl:parpl:t_testcochranpl The t-test with the Cochran-Cox adjustment The Cochran-Cox adjustment relates to the t-test for independent groups (1957) and is calculated when variances of analysed variables in both populations are different. The test statistic is defined by: The test statistic has the