What does it mean if there is a correlation of 0.67 (r=0.67) between exercising and grade point average? 67% of the variation in grade point average can be explained by exerising. We can not reject the null hypothesis and so exercising does not affect grade point average. There is a strong, postive relationship between exercising and grade point average. For each unit change in exercising, people's grade point average will increase by .67