Chi Squared Test Statistic Formula. A chi square χ2 statistic is a test that measures how a model compares to actual observed data. Expected value for the i th category.
Add together all of the quotients from step 3 in order to give us our chi square statistic. The data used in calculating a chi square statistic must be random raw mutually exclusive drawn. Observed value for the i th category.
This is the formula to calculate chi square statistics and is denoted by χ chi.
Since the test name itself is chi squared we calculate χ2 using the above formula. Expected value for the i th category. The chi square test of independence also known as the chi square test of association which is used to determine the association between the categorical variables. The motivation for performing a chi square goodness of fit test.
