Revision Notes: Statistics: Graphical Representation | Mathematics Class 10 ICSE PDF Download

Statistical data can be represented graphically by several ways.

• A histogram is a graphical representation of a frequency distribution (in continuous form) in the form of rectangles with class intervals as bases and corresponding frequencies as heights, with no gap between any two successive rectangles.
• Frequency polygons are another way of displaying data using straight line segments.
• The cumulative frequency is the accumulated or sum of frequencies up to a particular point. A table showing the cumulative frequencies is called a cumulative frequency distribution.
• Grouped data are also represented by a curve called ogive or cumulative-frequency curve.
• Construction of Cumulative Frequency Curve or an ogive:
  i. Construct a cumulative frequency table
  ii. Mark the actual class limits along x-axis
  iii. Mark the cumulative frequencies of respective classes along y-axis
  iv. Plot the points corresponding to cumulative frequency at each upper limit point.
  v. Join the points plotted by a free hand curve.
• An ogive is always started from a point on x-axis representing the lower limit of the first class and is terminated at the upper limit of the last class.
• An ogive is always a rising curve.