Class 8 Maths Data Handling Histograms

Histograms

A Histogram is a graphical representation of data like a bar graph with

• class intervals are represented on the horizontal axis.
• no gap between the bars as there is no difference between the class intervals.

For example, with the above frequency table of mathematics marks of 50 students, the following Histogram can be formed. Ajagged line (in red below) is made where data is not shown.

 Problem: For which of these would you use a histogram to show the data: (a) The number of letters for different areas in a postman’s bag. (b) The height of competitors in an athletics meet. (c) The number cassettes produced by 5 companies. (d) The number of passengers boarding trains from 7.00 a.m. to 7.00 p.m. at astation. Give reason for each. Solution: Since, Histogram is a graphical representation of data, if data represented in manner of class-interval. Therefore, for case (b) and (d), we would use a histogram to show the data, because in these cases, data can be divided into class-intervals. In case (b), a group of competitions having different heights in athletics meet. In case (d), the number of passengers boarding trains in an interval of one hour at astation.

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