Theory:

The frequency distribution of data can be represented in numerous ways. The graphical representation depends on the data itself.
 
Let us recall the two main divisions of data.
 
Ungrouped data:
When the data collected is a whole or exact measurement, it is an ungrouped data or discrete data.
Grouped data:
A grouped or continuous data is any value between a minimum value and a maximum value. In other words, continuous data will have values from a particular range. This type of data can be tabulated in the form of a frequency distribution table.
Depending upon the classification of data, graphical representation may vary.
 
Let us look at a few of them.
 
1276_1.svg
 
We will discuss histograms and frequency polygons in detail in the upcoming sections.
 
Let us now get introduced to histograms.
Histograms
Histograms are one way of graphically representing a grouped data; that is, histograms represent continuous data.
 
Histograms are made of a set of rectangles. \(X\)-axis will have the different ranges of continuous data, and \(Y\)-axis will have the frequency.
 
An example of a histogram is given below.
 
1276_2.svg
 
Important!
What is the difference between a bar graph and a histogram?
 
Bar graphs are used to represent discontinuous data. In other words, there are gaps between two frequency rectangles in a bar graph; while histograms are used to represent continuous data, and there are no gaps between two frequency rectangles.