Question

Marc, a high school senior, was given an eighth-grade science exam and he scored 85%. Is this an accurate predictor of how well students in the eighth-grade science class will perform on the exam?

A) No, because Marc is not representative of the population in the eighth-grade class
B) No, because Marc scored too high on the test
C) Yes, because Marc scored high so the test is easy
D) Yes, because Marc is representative of the population in the eighth-grade class

Answer 1

A) No, because Marc is not representative of the population in the eighth-grade class

Explanation:

You want to know if a high-school senior's performance on an 8th grade exam is an accurate predictor of 8th grade students' performance.

Predictor

One person's performance on one exam is not a predictor of anything.

Many factors affect individual performance on exams, and one individual's performance is rarely a predictor of the performance of a group.

If Marc were chosen specifically for the high correlation between his exam performance and the performance of 8th-grade science students, then perhaps one could argue Marc is representative of that population. We have no evidence of that being the case in this problem statement.

We must assume that Marc, a senior, is not representative of the 8th grade science class population, so his performance will not be a predictor of class performance.

<95141404393>