This bubble chart shows the correlation between average horsepower, torque, and highway MPG for various car makes. Each bubble’s position encodes horsepower (x-axis) and torque (y-axis), while its radius represents highway MPG. Bubbles are colored by car make, using a turbo colormap through `d3.interpolateTurbo` and `d3.scaleOrdinal`. An interactive tooltip displays the make on hover, implemented with `.on('mouseover')` callbacks. The chart also includes a size legend for MPG values derived from the `z` scale, with data drawn from `bubblechart.csv`.