- Bar graph is the graphical representation of the set of data.
- It is rectangular bar of equal width and the height of the bar is proportional to the value of data they represent.
- It has two lines, one horizontal line and one vertical line.
- The horizontal line represents the data type or the data categories.
- The vertical line represents the data value.
The graph below shows a bar graph of the number of food items that were sold in the shop.
Properties of Bar graphs
- All the bar must be equally spaced.
- The height of the bar represents the data value.
- The bar graphs must have a title, labels and scales.
- The data value must always start with 0.
Types of Bar graphs
- Horizontal bar graph
- Vertical bar graph
Horizontal Bar Graphs
- The data are arranged horizontally.
- In this graph the data type is in the vertical line and the data value is in the horizontal line.
- The bar runs from left to right.
Vertical Bar graphs
- The data are arranged vertically.
- In this graph the data type is in the horizontal line and the data value is in the vertical line.
- The bar runs from down to up.
Steps to draw Vertical Bar graphs
Interpret the Bar Graphs
- The title of the bar graph tells us what the data is about.
- The horizontal lines and the vertical lines represent the data type and the data value respectively.
- The horizontal bar graph below shows the graph of the favorite fruits of the group of students.
From the graph it can be visualized that:
- The bar representing the mango is the longest bar.
- The representing the orange is the shortest bar. Therefore, the least liked fruit is Orange.
- The scale of the graph is: 1 unit = 5 students.
- 10 students liked Apple.
- 20 students liked Mango.
- 5 students liked Orange.
- 15 students like Banana.
Therefore, most of the students like Mango.
Given below is the data of the number of students with their pets.
|Pets||Number of Students|
Draw a vertical bar that represents the given information and answer the following question:
- Which pet is kept by the maximum number of students?
- Which pet is kept by least number of students?
The vertical bar graph is:
- The graph shows that the maximum number of students liked cats.
- The graph shows that the minimum students liked rabbits.