# Bar Graph

## Bar Graph

A bar graph is a pictorial representation of data in which bars of uniform width are drawn with equal spacing between them on one x-axis depicting the variable. The value of the variable are shown on the y-axis, and the heights of the bars depend on the values of the variable.

Rules for drawing a bar graph:
a.  The events are written horizontally and the numbers are written vertically.
b.  All the bars drawn should have an equal width.
c.  Each bar is separated by an equal gap.
d.  Each bar should be colored with different colors.

Bar graphs are of two types:    i.  Simple bar graph
ii. Multiple bar graph

#### Simple bar graph:

Simple bar graph is constructed for the single component of the given data. Let us take an example of number of students and the subjects they liked in a survey among the students.

 Subjects English Maths Science Social No. of students 30 40 55 25

Simple bar graph:

From the above simple bar graph we can look for,
i.      How many students were asked the questions in the survey?
ii.     How many students like science?
iii.    Which is the most popular subject among the students? etc.

In this way, the simple bar graphs bar shows the result of a survey. The bar graph is very useful to compare the numbers of quantity of the same kind.

#### Multiple bar graph:

Multiple bar graph is constructed to present two or more related components of the given data. Let us take an example of number of boys and girls of different classes as given in the table below.

 Classes --> VIII IX X Boys 20 10 15 Girls 15 25 10

Multiple bar graph:

The above bar diagram shows the number of students of class VIII, IX and X. Here the number of boys and girls of each class is shown in different bar graphs. This is the example of multiple bar diagram.

### Workout Examples

Example 1: Represent the following data in a simple bar diagram.

 Grade I II III IV V No. of Bools 8 12 18 20 18

Solution: Here,
Simple bar diagram,

Example 2: The following information shows the mode of travel to school used by the students. Construct a multiple bar diagram.

 Walk School Bus Public Bus Bicycle Boys 80 60 60 15 Girls 100 50 70 10

Solution: Here,
Multiple bar diagram,

You can comment your questions or problems regarding the bar graphs here.