i. If we are testing for the difference between two population means, it is assumed that the sample observations from one population are independent of the sample observations from the other population.
Ii) If we are testing for the difference between two population means, it is assumed that the two
Populations are approximately normal and have equal variances.
Iii) When sample sizes are less than 30, a test for the differences between two population means has n
- 1 degrees of freedom.
A) (i), (ii) and (iii) are all correct statements
B) (i) and (ii) are correct statements, but not (iii).
C) (i) and (iii) are correct statements but not (ii).
D) (ii) and (iii) are correct statements but not (i).
E) All statements are false

Question

Quizplus · Accepted Answer

Statement (i) is correct as independence is a key assumption. Statement (ii) is correct for tests like the t-test assuming equal variances. Statement (iii) is incorrect; the degrees of freedom depend on the sample sizes of both groups, typically calculated using a specific formula.

I If We Are Testing for the Difference Between Two