Given the least squares regression line , and a coefficient of determination of 0.81, the coefficient of correlation is:
A) -0.66
B) 0.81
C) -0.90
D) 0.90

Question

Given the least squares regression line  , and a coefficient of determination of 0.81, the coefficient of correlation is:
A) -0.66 
B) 0.81 
C) -0.90 
D) 0.90

Quizplus · Accepted Answer

The coefficient of determination (R^2) tells us the proportion of variation in the dependent variable that is explained by the independent variable(s). The coefficient of correlation (r) gives us information about the direction and strength of the linear relationship between the two variables. The formula for r is the square root of R^2, which in this case is the square root of 0.81. Therefore, r is equal to 0.9, or choice D.

Given the Least Squares Regression Line , and a Coefficient