Final answer:
The decrease in percentile score of the graduating senior in their second attempt at the GRE could be due to difficulty, preparation, or natural variation. Percentile scores provide a relative measure of performance.
Step-by-step explanation:
When a graduating college senior takes the GRE (Graduate Record Exam) and scores at the 95th percentile, it means they performed better than 95% of the test takers.
However, when the same senior retakes the exam six months later after completing all undergraduate coursework and scores at the 89th percentile, it means they performed better than 89% of the test takers. The decrease in percentile score suggests a lower performance compared to their previous attempt.
Several factors could account for the lowered score:
Difficulty: The second exam could have been more difficult compared to the first one, resulting in a lower percentile score.
Preparation: The senior may not have prepared as well for the second exam, leading to a lower score.
Natural variation: Percentile scores can vary due to natural variation in test performance, even for the same individual.
It's important to note that while percentile scores can provide a relative measure of performance compared to other test takers, they don't provide an absolute measure of a student's abilities or knowledge.