This example shows a line chart of average scores for three subjects—Math, Reading, and Writing—derived from the StudentsPerformance dataset. It uses D3 v7 with SVG rendering, loading CSV data via `d3.csv`, then computing means with `d3.mean`. The chart employs `d3.scalePoint` for the categorical x-axis, `d3.scaleLinear` for the y-axis, and `d3.line` to draw the trend line, with red circles marking each average score.