Question

Which of the following may be used to check the conditions needed to perform a two sample test for mean (independent samples)?

I. Both populations are approximately normally distributed

II. Both sample sizes greater than 30

III. Population of differences is approximately normally distributed

A) I or III

B) II or III

C) I or II

D) I, II, or III

Answer 1

Option D is right

Explanation:

given that a two sample test for mean of independent samples to be done.

We create hypotheses as:

`H_0: \ bar x = \bar y` vs alternate suitably right or left or two tailed according to the needs.

The conditions needed for conducting this test would be

I. Both populations are approximately normally distributed

II. Both sample sizes greater than 30

III. Population of differences is approximately normally distributed

i.e. either i, ii or III

Option D is right.