Question

1. What do the t-tests, their non-parametric equivalents, the chi-square, and Fisher’s Exact Test all have in common?

Answer 1

Student’s t-test :  Test for continuous data. Investigates whether the expected values for two groups are the same, assuming that the data are normally distributed. The test can be used for paired or unpaired groups.

Fisher’s exact test :  Suitable for binary data in unpaired samples: the 2 x 2 table is used to compare treatment effects or the frequencies of side effects in two treatment groups

Chi-square test : Similar to Fisher’s exact test (albeit less precise). Can also compare more than two groups or more than two categories of the outcome variable. Preconditions: sample size >ca. 60. Expected number in each field ≥5.

the one common thing in these all test is that the all these tests are used for continuous data.