{"type":"rich","version":"1.0","title":"Proportion 4/20 = 7/x on the Desmos Graphing Calculator","html":"<iframe src=\"https://www.desmos.com/calculator/s7qwxggn38?embed\" width=\"500px\" height=\"500px\" style=\"border: 1px solid #ccc\" frameborder=0></iframe>","width":500,"height":500}