With simple examples, the bar-graph representation of Data is explained.

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In the earlier lessons, Data representation using tally marks, table, and pictograph were explained. What is the general use of these representations?

- to understand details like which data-value is large, which data-values are comparable, etc.
- to understand details like which data-value is large, which data-values are comparable, etc.
- the representations are not useful

The answer is "to understand details like which data-value is large, which data-values are comparable, etc."

The data can be given in a spatially laid out visual form. It is widely used in newspapers and other publications. Consider the data: Number of students who took a given fruit.

orange `2`

apple `2`

mango `5`

banana `1`

The figure depicts a "**bargraph**" of the data.

Which of the following is a meaning for the word "bar-graph"?

- data represented with bars
- data represented with bars
- a graph of straight-lines

The answer is "data represented with bars". The representation can be with horizontal or vertical bars.

What is the term used to refer "data represented with bars"?

- Pronunciation : Say the answer once

Spelling: Write the answer once

The answer is "bar-graph".

Earlier, we learned about scaling in pictographs. Scaling was introduced to represent large data-values. Does the bar-graph have a similar problem?

- No. Bar-graph does not have any problem in representing large values
- Yes. the numbers marked in vertical axis will be too close for large values.
- Yes. the numbers marked in vertical axis will be too close for large values.

The answer is "Yes. the numbers marked in vertical axis will be too close for large values."

Let us consider the data:

Orange : `15`

Apple : `10`

Mango : `30`

Banana : `5` Instead of marking each of the values in the vertical axis, the values are marked in increment of `5`. This is illustrated in the figure.

Let us consider the data:

Orange : `15`

Apple : `12`

Mango : `28`

Banana : `5` The number of apples `12` is represented with a vertical bar of height `12`.

Similarly the number of mangoes `28` is represented with a vertical bar of height `28`.

**Bar-Graph** : A spatial representation of data with bars in vertical and horizontal axis.

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