subtopic

Find the number of groups and a 2-D view

Run k-means for k = 2–8; plot inertia (elbow) and silhouette; pick k (3–5); plot PCA 2-D coloured by cluster. Concepts: k-means; elbow; silhouette; PCA view Project A: Expect 4 groups; check that no cluster has fewer than ~50 applicants. Project B: Optional: 3–4 day types.

Builds on: B19 · Build: See Your Data in 2-D (PCA)