[40 points]

The dataset used in this problem is related to the quality of white wine. The data includes 4898 samples of wine. There are 11 variables have potential effect to the response variable (quality). The data file winequality-white.txt and its description winequality-white_description.txt are uploaded on Canvas. The goal of this problem is to get you familiar with R and using R-packages to make the decision tree model and random forest model.

A) Using rpart R-package to make a decision tree and plot the tree. Which variable has the highest impact to the quality of white wine (show your result)?

B) Making a random forest model using the whole dataset, report your results. How does this result look like in comparison to part a?

Data sources:

http://archive.ics.uci.edu/ml/datasets/Wine+Quality

https://www.superdatascience.com/