Problem 3: Evaluate Model Fit with R² Score

Problem Description

Write a Python program that trains a Linear Regression model, makes predictions on the training data, and calculates the R² score to evaluate how well the line fits.

Input

Training data (X, y).

Output

The R² score.

Constraints

• At least 5 data points.

Example Input

text
X = [[1],[2],[3],[4],[5]], y = [2,4,5,4,5]

Example Output

text
R² Score: 0.6

Concepts Covered

r2_score().