12. As a student, you probably have noticed a curious phenomenon. In every class, there are some students who zip through exams and turn in their papers while everyone else is still on page 1. Other students cling to their exams and continue working until the very last minute. Have you ever wondered what grades these students get? Are the students who finish first the best in the class or are they simply conceding failure? To answer this question, we carefully observed a recent exam and recorded the amount of time each student spent working and the grade each student received.

Following are data for a sample of n 10 students.

a. Calculate the Pearson correlation between time and grade.

b. Based on the correlation, describe the relationship between time and grade. Do the highest grades go to the students who finish first or last?

c. Based on your answers to a and

b, do you think it would help your grades if you started turning in exams a little sooner? Explain your answer.

Time Exam

(in minutes) Grade 54 75 38 91 60 70 44 94 60 76 40 89 57 92 52 81 45 88 49 90