This visualization displays student test scores across favorite subjects, combining an animated orange bar chart with a static skyblue overlay showing average scores per subject. The code loads tab-separated data from a GitHub gist via `d3.text`, parses it into objects, and uses `d3.rollup` to compute subject means. It renders SVG bars with transitions, axes via `d3.axisLeft` and `d3.axisBottom`, and includes hover tooltips using D3 event handlers. The chart animates bars rising from the baseline using `.transition()`, and tooltips display individual subject and score data.