Graphic Representation of a Frequency Distribution

If you are a student of statistics or studying it as a part of mathematics, you must have come across the term frequency distribution.

Learning the concept of frequency distribution and its graphical representation is sometimes tough for students. In such cases, it is very important that the student develops interest in the subject and try to learn it in simple way. In this article, I will try to explain to you the graphical representation of a frequency distribution.
It is often useful to represent a frequency distribution by means of a diagram which makes the unwieldy data intelligible and conveys to the eye the general run of the observations. Diagrammatic representation also facilitates the comparison of two or more frequency distributions.

We will consider some important types of graphical representation: 1. Histogram: In drawing the histogram of a given continuous frequency distribution, we first mark off along the x-axis all the class intervals on a suitable scale.
On each class interval, erect rectangles with heights proportional to the frequency of the corresponding class interval so that the area of the rectangle is proportional to the frequency of the class.
If, however, the classes are of unequal width then the height of the rectangular will be proportional to the ratio of the frequencies to the width of the classes.

The diagram of continuous rectangles so obtained is called histogram. 2.
Frequency Polygon: For an ungrouped distribution, the frequency polygon is obtained by plotting points with abscissa as the variate values and the ordinate as the corresponding frequencies and joining the plotted points by means of straight lines.

For a grouped frequency distribution, the abscissa of points are mid-values of the class intervals.
For equal class intervals, the frequency polygon can be obtained by joining the middle points of the upper sides of the adjacent rectangles of the histograms by means of straight lines.

If the class intervals are of small width, the polygon can be approximated by a smooth curve.

The frequency curve can be obtained by drawing a smooth freehand curve through the vertices of the frequency polygon.
You can also take the help of private tutors to understand the graphical representation of a frequency distribution.
There are several online sites that provide information regarding private tutors in the U.

S.
So, find the right private statistic tutor in your locality and get all your doubts related to the subject cleared.