The following shows a history of users with attributes CS Major (i.e., majored in computer science), Age, and Income. We also indicate whether they will buy Bitcoin or not in the last column.

No.	CS Major	Age	Income	BuyBitcoin
1	yes	old	fair	yes
2	yes	middle	fair	yes
3	no	young	fair	yes
4	no	young	high	yes
5	yes	old	low	no
6	yes	young	low	no
7	no	young	fair	no
8	no	middle	low	no

We want to train a C4.5 decision tree classifier to predict whether a new user will buy Bitcoin or not. We define the value of attribute BuyBitcoin to be the label of a record.

1. Please construct a C4.5 decision tree according to the above example. In the decision tree, whenever (1) a node contains at least 80% records with the same label, or (2) a node contains at most 2 records, we stop further processing this node for splitting. Note that you should show the calculation of every attributes impurity gain at each step of the tree construction.
2. Consider a new young user studying CS whose income is fair. Please predict whether this new user will buy Bitcoin or not using the decision tree you trained.