I If Samples Taken from Two Populations Are Not Independent

question 37

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. The paired t test is especially appropriate when the sample sizes of two groups are the same.

• 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) (i) is a correct statement but not (ii) and (iii).

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Definitions:

Causal Variable

A causal variable is a factor that brings about change in another variable or set of variables, establishing a cause-and-effect relationship.

Correlational Method

A research technique that establishes the relationship (not necessarily causal) between two variables, traditionally denoted x and y, by measuring both variables in a sample of participants.

Random Assignment

Random assignment is a method used in experiments to randomly allocate participants to different groups, ensuring that each group is comparable at the start of the experiment.

Measurement Biases

Involves errors or inaccuracies in data collection, interpretation, or analysis due to systemic factors.