Question

A study of class attendance 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. Class attendance explained 81% of the variation in grade index among the students. What is the numerical value of the correlation between percent of classes attended and grade index

Answer 1

r = 0.9

Explanation:

Correlation is denoted by r. r² is usually used to measure variation along the line as a fraction of the total variation.

We are told class attendance explained 81% of the variation in grade index among the students. Thus, for this regression, the variation is;

r² = 81%

Or r² = 0.81

Thus, the numerical value of the correlation r would be;

r = √0.81

r = 0.9