What is the approximate depth of a Decision Tree trained(without restrictions) on a training set with 1 million instance?
Is node's Gini impurity generally lower or greater than its parent's? It is generally lower/greater, or always lower/greater?
generally lower than parent's
If a Decision Tree is overfitting the training set, is it good idea to try decresing max_depth?
Yes
If a Decision Tree is underfitting the training set, is it good idea to try scaling the input features?
No
If it take one hour to train a Decision tree on the training set containing 1 million instances. roughly how much time will it take to train another Decision Tree on a training set contain 10 million instances?
If your training set contains 100,000 instances, will setting presort=True speed up the training?
No
See Exercise.ipynb