Statistics II

Drawing Pie Diagram :
  • Find measure of central angle using formula (x / Total fi).3600.
  • Draw central angles on circle of convenient radius.

Drawing Histogram :
  • Make class intervals continuous.
  • Take extended class intervals on X-axis.
  • Take frequencies on Y-axis.
  • Draw rectangles on X-axis with base as extended class intervals.

Drawing Frequency Polygon or Frequency Curve :
  • Prepare frequency distribution table.
  • Draw X-axis, Y-axis, choose proper scale.
  • Take class marks on X-axis.
  • Take frequencies on Y-axis.
  • Plot the points.
  • Plot 2 additional points, one preceding the first class and another succeeding the last class, both with frequency 0.
  • In case of Frequency Polygon, join all successive points by straight lines.
  • In case of Frequency Curve, join all successive points by smooth freehand curve.