Question

How to determine if a t test or a F test is still valid ?

Answer 1

If the assumptions of the tests are met, then the tests are valid

For the t-test

i) The samples are randomly selected from a normal population with known mean

ii) If we are conducting 2 means comparison t-test, then the assumption is both the samples are independently generated from two normal population with equal variance

For the F-test, the assumptions are

i) Samples/observations are randomly selected

ii) Samples/observations are drawn from a normal population