Question

Which statistical test is used to compare mean of two identical group?

• A. ANOVA
• B. Sample t test
• C. Paired t test
• D. Pooled t test

Hint:

Use the paired t-test when comparing two related measurements (same group, different times or conditions) — crucial for bioequivalence and clinical trial designs in GPAT.

Answer 1

The Correct Option is C

The paired t-test is a statistical method used to compare the means of two related (i.e., identical or matched) groups. It is used when the same subjects are measured twice. for example, before and after a treatment, or under two different conditions. The test determines whether the average difference between paired observations is significantly different from zero. 

In the context of GPAT, it is essential for comparing pre- and post-treatment effects or evaluating crossover study designs in biostatistics and clinical trials. 

Other options: 

(A) ANOVA (Analysis of Variance) — Used when comparing means of more than two groups. 
(B) Sample t test (Unpaired/Independent t test) — Used to compare the means of two independent groups. 
(D) Pooled t test — A form of unpaired t-test that assumes equal variances in two independent samples.
 

Answer 2

The question asks which test is used to compare the means of two groups that are identical or matched, such as the same subjects measured twice. Let's go through each option:

1. ANOVA: Analysis of Variance is designed to compare the means of three or more groups at once. Using it for only two groups is unnecessary, and it is not built for paired or matched data specifically.
2. Sample t test: This usually refers to the independent or unpaired t test, which compares the means of two separate, unrelated groups of subjects, such as a treatment group versus a different control group. It assumes the two sets of observations come from different individuals.
3. Paired t test: This test compares two sets of measurements taken from the same subjects or matched pairs, for example blood pressure before and after a drug in the same patients. It works on the differences between each pair, which removes individual variation between subjects and makes the comparison more sensitive when the groups are identical or matched.
4. Pooled t test: This is a form of the independent t test used when two separate groups are assumed to have equal variances, so their variances are pooled together. Like the sample t test, it needs two different sets of subjects, not matched pairs.

Since the question specifically mentions two identical, meaning matched or related, groups, only the test built for paired data fits, which rules out ANOVA, the sample t test, and the pooled t test.

So the correct answer is Paired t test.