You are given study of class attendance of 9% and grades among first-year students at a state university showed that in general students who attended a higher percent of their classes earned higher grades. You are asked to find the numerical value of the correlation between percent of classes attended and grade index. To convert it into decimal, simply divide 9 by 100 and you will get 0.09.
The coefficent of variation is already 0.09 and so
r² = 0.09
Taking the square root of each sides to get the grade index,
√r² = √0.09
r = 0.03