6. (5 points) How can you validate your model? Give two distinctly different methods? 7. (5 points) Explain as if to a nonprofessional why adjusted-R might be better than R2. 8. (5 points) Define "parsimonious." Explain its relevance to building regression models. 9. (5 points) Explain how to incorporate categorical features into your model? Be specific. 10. (5 points) Compare and contrast the benefits and drawbacks of forward stepwise regression, backward stepwise regression, and all-possible regression