This example shows the price of a McDouble hamburger across fifteen US states, using horizontal bar marks to encode price along a linear scale. The chart is built with React and D3 v5, where React manages component state and SVG rendering while D3's `scaleBand` and `scaleLinear` compute positions and lengths. Data is loaded asynchronously from a CSV via `d3.csv`, and the visualization displays grid lines and axis ticks generated from the scales.