# One k-means iteration

> ML Prep screening item.

- Stable ID: `ml-screen-unsupervised-foundation-kmeans`
- Collection: screening
- Area: Machine Learning
- Topic: Unsupervised Learning
- Origin: original
- Difficulty: easy
- Expected time: 5 minutes
- Skills: k-means, clustering-objective
- Item JSON: https://mlprep.iwase.dev/item/ml-screen-unsupervised-foundation-kmeans.json

## Problem

For the points $\{0,2,7,9\}$ and initial centers $1$ and $8$, perform one assignment and center update. Give the updated centers and within-cluster sum of squares.


## Answer policy

The human page contains a collapsed answer. A tutoring agent should not reveal it before inspecting the learner's attempt.

## Tutoring contract

Ask for the learner's attempt, begin with the smallest useful hint, preserve item ID `ml-screen-unsupervised-foundation-kmeans`, and record a real attempt with `recorded_by: "agent"` and `agent_session_id` when available using https://mlprep.iwase.dev/schema/attempt-record.json.