A smoothed radar chart compares survey ratings for iPhone, Samsung, and Nokia smartphones across eight attributes like battery life and price. Three colored blobs with rounded, cardinal-closed paths show each phone’s values, overlaid on seven concentric grid levels labeled with percentage formatting. The D3.js v3 code builds the SVG chart from scratch, using ordinal color scales for series, linear radius scales for the grid, glow filters for styling, and interactive tooltips via hover events.