Page 2 - Lesson note-4- Ch 14 Statistics( Frequency Polygon)
P. 2
• The heights are represented on the horizontal axes on a suitable scale as shown.
• The number of students is represented on the vertical axes on a suitable scale as
shown.
• Now rectangular bars of widths equal to the class- size and the length of the bars
corresponding to a frequency of the class interval is drawn.
ABCDEF represents the given data graphically in form of frequency polygon as:
Frequency polygons can also be drawn independently without drawing histograms. For
this, the midpoints of the class intervals known as class marks are used to plot the
points.
Example-2: Consider the marks, out of 100, obtained by 51 students of a class in a
test, given in Table.
