 Solution

TODO: the model's explained-variance value is absent. For an ordinary least-squares linear regression with an intercept, the coefficient of determination is $R^2=1-S{S}_{\mathrm{residual}}/S{S}_{\mathrm{total}}$. Its value multiplied by one hundred is the corresponding percentage of sample variation explained by that fitted model. Read the actual reported $R^2$ and distinguish it from the adjusted coefficient of determination; neither is a verified prediction-performance estimate on new data. Without the missing summary or sums of squares, no numerical percentage can be recovered.