For students in a large lecture class, data from two variables, exam #1 score and exam #2 score, was collected. On each exam, the lowest score was 40 and the highest score was 100. The resulting least squares line is: When the line predicts y = __________ .
a) y = 100 - 0.5x
b) y = 50 + 0.5x
c) y = 80 - 0.5x
d) y = 60 + 0.5x