:6. In a certain class, midterm scores average out to 60, with
an SD of 15. The scores on the final exam have the same average
and SD. The correlation between the midterm scores and the final
scores is equal to 0.8. The best prediction for the final score
of a student whose midterm score is 90 is closest to
a. 75
b. 60

c. 90

d. 78

e. 84