If there is a +.20 correlation between SAT scores and high school GPA, SAT scores account for what % of the fluctuation in GPA?

If there is a +.20 correlation between SAT scores and high school GPA, SAT scores account for what % of the fluctuation in GPA?
Answer:
% of fluctuation is measured by coefficient of determination, R2
R2 = (0.20)2 = 0.04 or 4%
SAT scores account for 4% of the fluctuation in GPA.