This interactive D3.js scatterplot matrix visualizes relationships among three SAT score variables—TotalMath, TotalVerbal, and MathematicsAverageGPA—using U.S. state-level data from satscores.csv. Each cell shows a paired comparison of two variables, with points representing individual states. A hover effect changes point color to orange for enhanced readability. Built with d3.v7, the example uses d3.csv for data loading, d3.scaleLinear for axes, d3.cross to generate the grid of cell pairs, and d3.axisBottom/axisLeft with tick lines to render gridlines. The SVG rendering employs a coordinated [i,j] indexing system for placing points as circles.