If the coefficient of correlation between two variables is -0.9, then the coefficient of determination is........... .
a) 0.9
b) 0.81
c) 0.1
d) 0.19
To find the coefficient of determination, we need to square the coefficient of correlation. The coefficient of correlation measures the strength and direction of the linear relationship between two variables. Since the coefficient of correlation is -0.9, we square it to get the coefficient of determination.
(-0.9)^2 = 0.81
Therefore, the coefficient of determination is 0.81.
The correct answer is b) 0.81.