This example shows how to map two quantitative data fields—GPA and height—to screen positions using linear scales. The code defines an x-scale that translates GPA values into a horizontal range of 0 to 800 pixels, and a y-scale that maps height values to a vertical range of 500 to 0 pixels (reversed for typical Cartesian orientation). Both scales compute their domains dynamically from the data, expanding the minimum and maximum by 5% to add padding. The implementation uses D3.js’s `d3.scaleLinear` with explicit `.domain()` and `.range()` calls, relying on `d3.min` and `d3.max` to derive the input extents from the `data0` array.