For the Ridge regression model there is only one hyperparameter to optimize, alpha, which was set to 9 after scanning over a range of values and finding the one with the highest score. Similarly, for the Kernel Ridge Regression model we tested linear and polynomial kernels and found that a third-degree polynomial kernel gives the best result. The alpha parameter was set to 60 after optimization by scanning over a range of values and finding the one that gave the highest score.