I If Samples Taken from Two Populations Are Not Independent

Multiple Choice

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) .