This project is completed jointly by Yixu Wang, Jiaqi Dong, Rui Zhu.
The dataset used can be found from https://archive.ics.uci.edu/ml/datasets/Beijing+PM2.5+Data
2. Come out with some hypothese that which predictors are not significant (Nested model + ANOVA)(Rui Zhu)
4. Variable selection (Rui Zhu)(which variables to keep, based on previous results and AIC, BIC or PRESS test)
###### 4.1 Linearity<br/>
###### 4.2 Normality<br/>
###### 4.3 Equal variance<br/>
###### 4.4 Independence using time series (difficult)<br/>