This bubble chart visualizes the correlation between life expectancy, population, and GDP per capita for a small set of countries. Each circle's x-axis position encodes life expectancy, its y-axis position encodes population, and its radius and color encode GDP per capita. The visualization uses D3.js (v7) with SVG rendering, and on hover, a tooltip displays the country name. The code applies `d3.scaleLinear` for axes and bubble size, `d3.scaleOrdinal` with an `interpolateTurbo` color scale, and legends for GDP values and country colors. Data comes from the included `bubblechart.csv` file.