The chi-square test is one of the most common ways to examine relationships
between two or more categorical variables example heart rate with Horror movie.Fisher’s Exact Test (often called simply Fisher’s or F test) is a nonparametric test often substituted for the chi-square test with small or sparsely distributed data sets like Solar flares and Electrical blackout. McNemar’s test is a type of chi-square test used when the data comes from paired samples like Heart rate before and After seeing a horror movie or a Presidential candidate.
You can also use the test for combinations of factors (e.g. the incidence of blue/brown eyes in people with light/dark hair, or the numbers of oak and birch trees with or without a particular type of toadstool beneath them on different soil types, etc.).
These test is used to determine whether there is a significant association between the two variables.They are mainly employed in Research.