In: Statistics and Probability
When we estimate a linear multiple regression model (including a linear simple regression model), it appears that the calculation of the coefficient of determination, R2, for this model can be accomplished by using the squared sample correlation coefficient between the original values and the predicted values of the dependent variable of this model.
Is this statement true? If yes, why? If not, why not? Please use either matrix algebra or algebra to support your reasoning.
this statement is completely false because the calculation of the coefficient of determination, R2, for this model can be accomplished by using the squared sample correlation coefficient between the independent and dependent variable of this model.
there is perfect correlation between the original values and the predicted values so this is not possible to sya that the square of it is coefficient of determination.
let us consider
(x) | (Y) |
9 | 98 |
12 | 186 |
16 | 203 |
18 | 159 |
35 | 263 |
the correlation coefficient is 0.8448
coefficient of determination is 0.7136
whereas
(x) | (Y) | estimated value |
9 | 98 | 585.117 |
12 | 186 | 1028.766 |
16 | 203 | 1114.471 |
18 | 159 | 892.6463 |
35 | 263 | 1416.958 |
the correlation coefficient is 1
coefficient of determination is 1 which is not possible