Statistics

• Construction of histogram of different class intervals

A histogram is a graphical representation of grouped data.

 

Example: 

Represent the given data in the form of a histogram.

 

Marks	0 – 20	20 – 30	30 – 50	50 – 60
Number of students	10	13	16	11

 

Solution:

Here, the minimum class size is 10.

Thus, we can find the adjusted frequencies using the following formula,

 

 

Marks	Number of students	Class size	Adjusted frequency
0 – 20	10	20
20 – 30	13	10
30 – 50	16	20
50 – 60	11	10

 

The histogram of the given data can be drawn as follows:

• Interpretation of histograms

The interpretation of data represented by a histogram can be done by looking at it.

Example:

The following histogram shows the production of food grains (in thousand tonnes) over a period …