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. These representations were useful 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.
The word "bar-graph" means: data represented with bars. The representation can be with horizontal or vertical bars.
familiarize with the terminology
bar-graph
Earlier, we learned about scaling in pictographs. Scaling was introduced to represent large data-values.
The bar graphs have a similar problem. 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.