Data Science Quiz

Example Questions From the Test

• 8A data scientist wants repeated runs of the same random train-test split to select the same records. What is the most direct step?
  • Add more rows after each run
  • Set and record the random seed used by the splitting procedure
  • Sort the target values from highest to lowest before splitting
  • Remove the target column before saving the dataset
• 13A table named sales contains region and revenue columns. Which SQL query correctly calculates average revenue for each region?
  • SELECT region, AVG(revenue) FROM sales GROUP BY revenue;
  • SELECT region, AVG(revenue) FROM sales GROUP BY region;
  • SELECT AVG(region), revenue FROM sales GROUP BY region;
  • SELECT region, revenue FROM sales WHERE revenue = AVG(revenue);
• 16A model achieves 99% accuracy on its training data but only 68% accuracy on unseen test data. Which explanation is most likely?
  • The model is overfitting patterns specific to the training data
  • The model is underfitting because both scores are equally low
  • The target variable must be continuous
  • The test data have been used too many times during training