This interactive bubble chart visualizes the relationship between engine displacement and fuel economy for a dataset of cars, sourced from a CSV file. Each bubble’s size encodes vehicle weight, while its color represents the number of cylinders. Built with D3 v7, the SVG chart uses `d3.scaleLinear`, `d3.scaleSqrt`, and `d3.scaleOrdinal` to map data to positions, radius, and color. Hovering a bubble triggers a tooltip, and the chart includes axes, gridlines, and a legend for filtering by cylinder count.