i. If samples taken from two populations are not independent, then a test of paired differences is applied.
Ii) The paired difference test has (n1 + n2 - 2) degrees of freedom.
Iii) A statistics professor wants to compare grades of two different groups of students taking the same
Course in two different sections. This is an example of a paired sample.
A) (i), (ii) and (iii) are all correct statements
B) (i) and (ii) are correct statements, but not (iii).
C) (i) is a correct statement, but not (ii) or (iii).
D) (ii) and (iii) are correct statements but not (i).
E) (ii) is a correct statement, but not (i) and (iii).

Question

Quizplus · Accepted Answer

Statement (i) is correct because a paired difference test is used when samples are not independent. Statement (ii) is incorrect because the paired t-test uses n-1 degrees of freedom, where n is the number of pairs. Statement (iii) is incorrect because comparing two different groups is not a paired sample scenario.

I If Samples Taken from Two Populations Are Not Independent