Week 9 revised analysis building multiple regression model with living area, quality rating, and central air variables. Includes comprehensive diagnostics using the 5 plots from class: residuals vs fitted, residuals vs X values, correlation heatmap, residual histogram, and Q-Q plot. Evaluates linearity, normality, homoscedasticity, and multicollinearity with severity assessments and confidence levels for each assumption.

基于回归的方法，总结了连续/二分类结局及中介变量组合下的因果中介分析方法及 R 代码实现