Scores on a chemistry exam were mound-shaped with a mean score of 90 and a standard deviation of 64. Scores on a statistics exam were also mound-shaped, with a mean score of 70 and a standard deviation of 16. A student who took both exams achieved a grade of 102 on the chemistry exam and a grade of 77 on the statistics exam. Which of these may be inferred from the information given?
A) The student did relatively better on the chemistry exam than on the statistics exam, compared to the other students in each class.
B) The student did relatively better on the statistics exam than on the chemistry exam, compared to the other students in the two classes.
C) The student's scores on both exams are similar when accounting for the scores of the other students in the two classes.
D) Without more information it is impossible to say which of the student's exam scores indicates the better performance.

Question

Quizplus · Accepted Answer

The student's z-score for the chemistry exam is (102-90)/64 = 0.1875, and for the statistics exam is (77-70)/16 = 0.4375. The higher z-score for the statistics exam indicates a better relative performance compared to peers.

Scores on a Chemistry Exam Were Mound-Shaped with a Mean