Bar graph

• A bar graph is a graph that shows complete data with rectangular bars.
• Bar graphs are a pictorial representation of grouped data and it is one of the ways of data handling.

Properties of Bar graph

• All rectangular bars should have equal width and should have equal space between them.
• The bars in the graph can be shown vertically or horizontally.
• The height of the bar is proportional to the values they represent.
• The rectangular bars must be on a common base.

How to Draw a Bar graph?

Let us see an example of Bar graph.

Examples:

The number of students in three different classes of a school is given below. Represent the data on a bar graph.

Answer:

The number of students is represented by the vertical lines and the classes are represented through the horizontal lines. Here is the complete picture of the bar graph.

Uses of Bar graph

• The comparisons between different variables are different and easy and convenient.
• It is very easy to prepare a diagram of a bar graph.
• It is a widely used variation of data handling. Therefore, it is used by various industries.
• If the frequency of data is very large then bar graphs are always more useful. As pictographs become time-consuming and very difficult in such cases.

Interpretation of Bar Graph

• Understand the data presented on the horizontal line and the vertical line.
• Know the relationship between the horizontal line and the vertical line in terms of the height of the bars.
• Observe the fixed intervals along the vertical lines.

Examples:

Here is bar graph drawn on how many students like apple, orange, and mango.

Observe the given bar graph and answer the following questions.

1. How many students like apple?
2. How many more students like apple than mango?
3. What is the total number of students who like orange and mango?

   Answer:

   Here along the vertical line number of students are represented and horizontal line fruits are represented.

   1. 20 students liked apples.
   2. 20 students like apple and 12 students like mango.

      So, 20 – 12 = 8

      8 students like apple as fruit than mango.

   3. From the graph, it is clear that there are 15 oranges and 12 mangoes.

      So, the total number of oranges and mangoes are 15 + 12 = 27.