**Data Handling**

Bar Graph

A bar graph is a graphical representation of data, by rectangular bars.

- Data can be represented by bars.
- In a bar graph each bar represents a number.
- The length of bars represents numerical value.
- In a bar graph, bars can be drawn vertically or horizontally.

Example:In a school, there are 15, 20, 45, and 39 students with yellow, red, blue, and green dresses, respectively. We can represent this data using a bar graph:

To make a bar graph, we need:

**Data categories:**Type of things in the data.

**Data value:**Numerical value of each category.

**Scale:**To draw the bar with numbers by scaling.

**Title:**We need to give an appropriate title to the graph.

- In a bar graph, there should be equal spacing between the bars.

Types of bar graph

Vertical bar graph

- In vertical bar graphs, the bars are drawn vertically to represent the data.

Example:

The number of children in five different batches of an educational institute is given below by a vertical bar graph.

Here, 1 unit length = 10 children.

From this graph, we can find

Question:

What is the number of students in Batch 3?

Answer:

From the graph, the number of students in batch 3 is 40.

Question:

The maximum number of students present in which batch?

Answer:

The maximum number of students present in batch 2, the number of students is 50.

Horizontal bar graph

- In the horizontal bar graph represents the data by the horizontal bars.

Example:

The data for the baking of cakes in a bakery from Monday to Saturday is shown below by a horizontal bar graph.

1 unit = 10 cakes

Question 1:

Maximum numbers of cakes baked on which day?

Answer:

Question 2:

Minimum numbers of cakes baked on which day?

Answer:

Minimum numbers of cakes baked on Monday.

Steps to make a bar graph

Let us consider,

We have four different types of animals, such as cat, dog, rabbit, and hamster and the corresponding numbers are 40, 30, 10, and 70 respectively.

The bar graph becomes as given below:

**Note: Scale: 1 unit=10 animals.**

Transformation of a horizontal bar graph to a vertical bar graph:

From this graph, we can make the table

The following table shows number of visitors to park for the months January to March

Month |
January | February | March |

Month |
150 | 300 | 250 |

Also, from the graph we have

- The greatest number of visitors come to the park in February.
- Also, the maximum number of visitors in one month is 300.
- The number of visitors that come in March is 250.
- The minimum number of visitors comes in January.
- The number of visitors that come in January is 150.

**Also, we can make the vertical graph by the similar data:**

Advantages of bar graph

- Bar graph summaries the large set of data in simple visual form.
- Bar graph displays each category of data in the frequency distribution.
- Bar graph displays each category of data in the frequency distribution.
- The bar graph clarifies the trend of data better than the table.
- Bar graph helps in estimating the key values at a glance.

The disadvantage of bar graph

- Sometimes, the bar graph fails to reveal the patterns, cause, effects, etc.
- It can be easily manipulated to yield fake information.

Did you know?

Bar graph use to show the increase of daily cases of coivd-19