This example demonstrates how to format tick labels on a D3.js axis using custom tick formatting. A linear scale maps a domain of 0 to 100 to a pixel range, and an axis bottom is configured with increased tick padding and size. The axis is customized by limiting the number of ticks to four and applying a custom `tickFormat` function that appends a percent sign to each value. The resulting SVG renders the axis with labeled ticks showing the original data values with a “%” suffix.