This pie chart visualizes the average car price by brand, using a dataset of 50 vehicles across ten manufacturers. Each slice represents a brand, with its size determined by the mean price of its cars, and labels display the brand name and average value. The chart is built with D3 v7, using `d3.pie()` to compute arc data, `d3.arc()` to render the slices as SVG paths, and `d3.scaleOrdinal` with the `schemeSet3` color palette. Average prices are calculated via `d3.rollup` and `d3.mean` before the pie is drawn.