This bubble chart visualizes the correlation between average life expectancy, population, and GDP per capita for six countries using a CSV dataset. Each circle’s position maps to life expectancy and population on the x and y axes, while its radius encodes GDP per capita and its color distinguishes countries via a `d3.scaleOrdinal` with interpolated turbo colors. Interactive tooltips appear on hover using mouse events. A legend includes size reference circles and color swatches, all rendered with SVG in D3 v7.