This interactive dashboard combines a bar chart and a pie chart to explore categorical frequency data across states. Hovering over a bar updates the adjacent pie chart and legend to display the breakdown of that state’s frequency by three categories (low, mid, high), with smooth transitions between states. Built with React and D3.js v3, the visualization uses SVG paths for the pie slices and rects for the bars, with mouseover and mouseout handlers triggering `pC.update()` and `leg.update()` to synchronize the views. The bar chart’s y-axis rescales dynamically as the pie selection changes the underlying data.