To find the optimal number of clusters (k), which method is commonly used to find the “kink” in the graph?

Below is the Elbow Method output from your K-Means analysis. The y-axis is Total Within-Cluster Sum of Squares (WSS). What is the BEST k to choose, and why?

Among the metrics for evaluating decision tree complexity, which one is described as the ‘gold standard’?

Why do we need Multiple Linear Regression?

In a Random Forest, every tree is trained on EXACTLY THE SAME data with EXACTLY THE SAME feature set, so all trees end up making identical predictions.

After running K-Means with k=3, your team produced the cluster profile below comparing means across causal variables. Cluster 2 has the HIGHEST average Total Infections by far, while Cluster 1 has nearly zero infections AND low CPI/Corn Price. What is the BEST business label for these clusters?

What is a key LIMITATION of Mean Decrease in Gini as a feature importance metric?

In the Transformer architecture, what does the DECODER have that the ENCODER does NOT have?

A decision tree is a __________ algorithm used for both classification and regression analysis.

Your client (a fund manager) asks you to explain what kinds of Polymarket markets the decision tree below classifies as ‘High Interest’ (predicted = 1). Looking at the tree, which path leads to the High Interest label?