3.select("#my_dataviz")
  .append("svg")
    .attr("width", width + margin.left + margin.right)
    .attr("height", height + margin.top + margin.bottom)
  .append("g")
    .attr("transform",
          "translate(" + margin.left + "," + margin.top + ")");

//Read the data
d3.csv("https://raw.githubusercontent.com/holtzy/data_to_viz/master/Example_dataset/4_ThreeNum.csv", function(data) {

  // Add X axis
  var x = d3.scaleLinear()
    .domain([0, 12000])
    .range([ 0, width ]);
  svg.append("g")
    .attr(