Databricks Certified Machine Learning Associate — Question 19

A data scientist uses 3-fold cross-validation when optimizing model hyperparameters for a regression problem. The following root-mean-squared-error values are calculated on each of the validation folds:
• 10.0
• 12.0
• 17.0
Which of the following values represents the overall cross-validation root-mean-squared error?

Answer options

• A. 13.0
• B. 17.0
• C. 12.0
• D. 39.0
• E. 10.0

Correct answer: A

Explanation

The overall cross-validation root-mean-squared error is calculated by taking the average of the RMSE values from the folds. In this case, (10.0 + 12.0 + 17.0) / 3 = 13.0, which is the correct answer. The other options do not represent the average of the given RMSE values.