Refer to the Prostate cancer data set in Appyndix. Build a regression model to predict PSA level (Y) as a function of cancer, Volume (X). The analysis should include an assessment of the degree to which the key regression assumptions are satisfied. If the regression assumptions are not met, include and justify appropriate remedial measures. Use the final model to estimate mean PSA level for a patient whose cancer volume is 20 cc. Assess the strengths and weaknesses of the final model.