This scatter plot visualizes a synthetic fitness dataset of 150 individuals, showing the relationship between hours of exercise per week (x-axis) and calories burned per week (y-axis). The points are colored by four activity-level clusters—Sprinters, Marathoners, Crossfitters, and Yoga Enthusiasts—using a D3 ordinal color scale. Built with D3 v7, the visualization uses `d3.select`, `d3.scaleLinear`, `d3.scaleOrdinal`, and the `join` pattern to render axes, circles, and an interactive tooltip. The data is procedurally generated with a seeded random function to create natural-looking cluster distributions.