Statistical Methods DY0-001 Practice Questions (Page 4)

Questions 16–20

1. 16foundation · easy

   What does the area under the ROC curve (AUC) measure?

   • AThe accuracy of the model at a specific threshold
   • BThe precision of the model
   • CThe overall ability of the model to distinguish between positive and negative classes
   • DThe recall of the model
   Reveal Solution Discussion Select an answer first
2. 17foundation · easy

   In a binary classification problem, when is entropy at its maximum?

   • AWhen the sample size is very large
   • BWhen the data are normally distributed
   • CWhen the classes are perfectly balanced (50/50)
   • DWhen all samples belong to one class
   Reveal Solution Discussion Select an answer first
4. 18foundation · easy

   What does the Gini index measure in the context of a dataset?

   • AThe inequality or impurity of a distribution
   • BThe central tendency of a dataset
   • CThe correlation between two variables
   • DThe spread or variability of a dataset
   Reveal Solution Discussion Select an answer first
5. 19application · medium

   A data scientist is building a decision tree to classify loan applicants as 'default' or 'no default'. The root node currently has 100 applicants, with 50 in each class. She is evaluating a split on the feature 'credit_score' that creates two child nodes: Node 1 has 40 applicants (30 default, 10 no default) and Node 2 has 60 applicants (20 default, 40 no default). What is the Gini index of the parent node?

   • A1.0
   • B0.5
   • C0.75
   • D0.25
   Reveal Solution Discussion Select an answer first
6. 20foundation · easy

   What does an AUC of 0.5 indicate about a binary classification model?

   • AThe model has perfect discrimination
   • BThe model is overfitting the training data
   • CThe model performs no better than random chance
   • DThe model has high precision but low recall
   Reveal Solution Discussion Select an answer first