Question 935398
The value r^2 is a fraction between 0.0 and 1.0, and has no units. An r^2 value of 0.0 means that knowing X does not help you predict Y. There is no linear relationship between X and Y, and the best-fit line is a horizontal line going through the mean of all Y values. When r^2 equals 1.0, all points lie exactly on a straight line with no scatter. Knowing X lets you predict Y perfectly. 
For your problem Y is college GPA's and X is high school GPA's, therefore an r^2 = 0.311 implies that there is a 31.1% correlation between X and Y.
answer is B