Question

when conducting hypothesis tests regarding the differnce in means across two population, an important assumption is that ??

Answer 1

To test whether there is a difference between population means or not, we are going to make three assumptions:

1) The two populations have the same variance. This assumption is called the assumption of homogeneity of variance.although we can also test without having the same variances of population as wilk t test can be applied if population standard deviation in unknown.

2) The populations are normally distributed.this is the main assumption to apply parametric test.

3) Each value is sampled independently from each other value. i.e the samples are independently drawn from their population. as i think this can be an important assumption to conduct hypothesis tests regarding the differnce in means across two populations.