In a regression tree, a node split is chosen to minimize which of the following?

In a decision tree, what does a leaf node represent? 

Assume that you build a model for predicting consumer credit ratings and you evaluate it on a testing dataset of 5 records. The table below shows 5 actual credit ratings and the corresponding predictions.    Predicted Credit Rating Actual Credit Rating 730 750 630 660 600 570 800 680 640 690

In what situation would you recommend using a regression tree over k-NN for a numeric prediction task?

What is the Precision of the model for Spam?

This question is based on the graph and table above. Next, assume you run k-NN and use k = 6. Determine the nearest neighbors and determine how the new observation X would be classified.

Is the selection of k=6 a good choice for the model data? Explain your answer.

This question is based on the graph and table above. Assume you run k-NN and use k = 3. Using the distances reported in the table above, identify the nearest neighbors and determine how the new observation X would be classified (red or green).

  Utilize the following confusion matrix from an email spam detection model for the next 3 questions:   True Class – Spam True Class – No Spam Predicted – Spam 40 60 Predicted – No Spam 10 90  

Which of the following environmental agents has been associated with breakage of chromosomes?