This interactive scatter plot visualizes the relationship between horsepower and MPG for a sample of cars from the Cars dataset, encoding each vehicle’s weight through circle radius and origin through color (USA, Japan, Europe). Using D3.js v7, the code builds SVG axes and circles, mapping quantitative scales for horsepower, MPG, and weight, while color categories are hardcoded. Hovering a circle reveals a tooltip with the car’s specific measurements, implemented via D3’s event handling and the `d3.select` API.