Final answer:
The correct answer is a test of dependent means or matched pairs, because the data is likely to be correlated due to the subjects being identical twins. These twins might share genetics and environmental factors, which makes their GPAs dependent on each other.
Step-by-step explanation:
The college GPA's of identical twins being compared to see whether the means are different involves a statistical test. The type of test needed here depends on whether the twin pairs are considered independent groups or matched or paired samples. In this scenario, because the subjects are identical twins, the data is likely to be correlated.
Therefore, the appropriate statistical test is a test of dependent means, also known as a matched pairs test (since each twin in a pair shares genetics and possibly environmental factors).
When comparing the means of two related groups, such as in the case of identical twins, one should use tests designed for dependent samples, because the observations within each twin pair are not independent from each other.
An example illustrating independent samples would be a comparison between the GPAs of students from two different schools, where students from one school have no relation to students from the other school. However, in the case of identical twins, especially if we consider scenarios where they might have been raised together or share similar environmental influences despite being raised apart, there is a strong case for the pairs to be dependent.
This is supported by findings, such as those from the Minnesota Study of Twins Reared Apart, indicating that identical twins have highly correlated traits regardless of upbringing.