A scatter plot displays the relationship between vehicle weight and fuel efficiency (MPG) for cars from the 1970s, with each circle’s size proportional to weight. Using d3.csv to load the data, d3.scaleLinear maps the x- and y-domains, while d3.axisBottom and d3.axisLeft render gridlines and ticks. The SVG circles are appended via data joins, and margins define the plotting area.