Now we will discuss about the construction of bar graphs or column graph.
In brief let us recall about, what is bar graph?
graph is the simplest way to represent a data.
● In consists of rectangular bars of equal width.
● The space between the two
consecutive bars must be the same.
● Bars can be marked both
vertically and horizontally but normally we use vertical
● The height of bar
represents the frequency of the corresponding observation.
example, let us observe the following data of the
The following data
gives the information of the number of children involved in different
|No. of Children||30||40||25||20||53|
How to Construct a Bar Graph?
of bar graphs/column graph:
● On a graph, draw two
lines perpendicular to each other, intersecting at 0.
● The horizontal line is
x-axis and vertical line is y-axis.
● Along the horizontal
axis, choose the uniform width of bars and uniform gap between the
bars and write the names of the data items whose values are to be marked.
● Along the vertical axis,
choose a suitable scale in order to determine the heights of
the bars for the given values. (Frequency is taken along y-axis).
● Calculate the heights of
the bars according to the scale chosen and draw the bars.
Bar graph gives the information of the
number of children involved in different activities.
Solved examples on construction of bar graphs:
1. The percentage of total income spent
under various heads by a family is given below.
|Different Heads||Food||Clothing||Health||Education||House Rent||Miscellaneous|
|% Age of Total
Represent the above data in the form of bar
2. 150 students of class VI have popular
school subjects as given below:
|Number of Students||30||20||26||38||34|
Draw the column graph/bar graph
representing the above data.
Take the subjects along x-axis, and the number of students
Bar graph gives the information of
favourite subjects of 150 students.
3. The vehicular traffic
at a busy road crossing in a particular place was recorded on a particular day
from 6am to 2 pm and the data was rounded off to the nearest tens.
|Time in Hours||6 – 7||7 – 8||8 – 9||9 – 10||10 – 11||11 – 12||12 – 1||1 – 2|
|Number of Vehicles||100||450||1250||1050||750||600||550||200|
Bar graph gives the information of number
of vehicles passing through the crossing during different intervals of time.
about The Math.