Consider the following OLS regression lines obtained from a random sample of 200 students: = 2 + 0.03ACT (1) and= 2 + 0.01ACT + 0.5 hsGPA (2), where colGPA is college grade point average, hsGPA is high school GPA and ACT is achievement test score.

Consider the following OLS regression lines obtained from a
random sample of 200 students: = 2 + 0.03ACT (1) and
= 2 + 0.01ACT + 0.5 hsGPA (2), where colGPA is college
grade point average, hsGPA is high school GPA and ACT is
achievement test score. Both colGPA and hsGPA are on a fourpoint scale. ACT are tests taken by students when they were in
high school, to assess their readiness to attend college. Which of
the following statements is correct?
According to equation (1), an increase in ACT score by 10
points is predicted to increase colGPA by 0.03 point.
According to equation (1), an increase in ACT score by 10
points is predicted to increase colGPA by 0.3 point, holding
hsGPA fixed.
According to equation (1), an increase in ACT score by 10
points is predicted to increase colGPA by 0.3 point.
According to equation (1), an increase in ACT score by 10
points is predicted to increase colGPA by 0.03 point,
holding hsGPA fixed.