A bar chart compares average grade improvement across AI tool purposes, with each bar height representing the mean grade change for that category. The chart highlights how different reasons for using AI correspond to varying academic outcomes. Built with D3 v7, it loads CSV data via `d3.csv`, aggregates values using `d3.rollups` and `d3.mean`, and scales axes with `d3.scaleBand` and `d3.scaleLinear`. Rendered as SVG, bars include hover tooltips for detail, and the chart is sorted from highest to lowest average improvement.