Given Sxx=∑(Xi−Xˉ)2=40S_{xx} = \sum (X_i - \bar{X})^2 = 40Sxx=∑(Xi−Xˉ)2=40, Syy=∑(Yi−Yˉ)2=90S_{yy} = \sum (Y_i - \bar{Y})^2 = 90Syy=∑(Yi−Yˉ)2=90, and Sxy=∑(Xi−Xˉ)(Yi−Yˉ)=30S_{xy} = \sum (X_i - \bar{X})(Y_i - \bar{Y}) = 30Sxy=∑(Xi−Xˉ)(Yi−Yˉ)=30, what is the coefficient of determination R2R^2R2?
0.250.250.25
0.330.330.33
0.500.500.50
0.670.670.67