What is a frequency polygon used for

what is a frequency polygon used for

What is frequency polygon What are its uses?

Aug 11,  · Tables, graphs, pie-charts, bar graphs, histograms, polygons etc. are used to represent statistical data pictorially. Frequency polygons are a visually substantial method of representing quantitative data and its frequencies. Let us discuss how to represent a frequency polygon. Steps to Draw Frequency Polygon. May 25,  · A frequency polygon is a visual representation of a distribution. The visualization tool is used to understand the shape of a distribution. Essentially, the frequency polygon indicates the number of occurrences for each distinct class in the dataset. In addition, the graph may be used to show the cumulative frequency distribution.

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Graphical display of the frequency table can also be achieved through a frequency polygon. To create a frequency polygon the intervals are labeled on the X-axis and the Y axis represents the height of a point in the middle of the interval. The points are then joined are connected to the X-axis and thus a polygon is formed.

So, frequency polygon is a graph that is obtained by connecting the middle points of the intervals. We can create a frequency polygon from polgon histogram also.

If the middle top points of the bars of the histogram are joined, a frequency polygon is formed. Frequency polygon and histogram fulfills the same purpose. However, the former one is useful in comparison of different datasets. In addition how to write a rsvp letter that frequency polygon can be used to display cumulative frequency distributions. As already mentioned, histogram can be used for creating frequency polygon.

The X-axis represents the scores of the dataset and the Y-axis represents the frequency for each of the classes. Now, mark the mid top points of each bar of the created histogram for each class interval. One generally uses a dot for marking. Now join all the dots by straight lines and what is a frequency polygon used for it with the X-axis on both sides. For creating a frequency polygon without a histogram, you just what is a frequency polygon used for to consider the midpoint of the class intervals, such that it corresponds to the frequencies.

Then connect the points as stated hwat. The following table is the frequency table of the marks obtained by 50 students in the pre-test examination. Table 1. Frequency Distribution of drequency marks obtained by 50 students in the pre-test examination. The labels of the X-axis are the how to thin hair on arms of the class intervals.

So the first label on the X-axis will be The corresponding frequencies are then considered to create the frequency polygon. The shape of the distribution can be determined from the created frequency polygon. The frequency polygon is shown in the following figure. Fig 1: Frequency polygon of the distribution of the marks obtained by 50 students in the pre-test examination. Cumulative frequency polygon is similar to a frequency polygon.

The difference is that in creating a cumulative frequency polygon we consider cumulative frequencies instead of actual frequencies. Cumulative frequency of less than type is obtained x adding the frequency of each class interval to the sum of all frequencies in the lower intervals.

In table 1 for example, the cumulative frequency for the class interval Again the cumulative frequency for the class interval Fig2: Cumulative Frequency polygon of the marks obtained by frequenvy students in the pre-test us. Also to compare the distributions of different data sets, frequency polygon can be used. In such case frequency polygons of different data are drawn on the same graph. The above thing can be made clear through illustrations. The following is an example of dice where the distribution of observed frequencies and the distribution of expected frequencies are compared for different scores of two dice.

The frequency curves of the two distributions are used for comparison. The observed curve overlaps expected curve. The expected curve is smooth while the observed curve is not smooth.

Also cumulative sued polygon can also be plotted in the same graph. The following figure shows such plot. The marks of two papers are compared through cumulative frequency polygon. Statistical help and online statistics help provided by us will thus help you to learn the proper use and various aspects of statistics.

Cumulative frequency polygons - creation and interpretation. Overlaid frequency polygons - creation and interpretation. Frequency Polygons: Graphical display of the frequency table can also be achieved through a frequency polygon. How to Create a Frequency Polygon? Class Boundaries Frequency Cumulative frequency Less than type From the above figure we can observe that the curve is asymmetric and is right skewed.

Cumulative Frequency Polygon: Cumulative frequency polygon is similar to a frequency polygon. The following is the cumulative frequency polygon Fig2: Cumulative Frequency polygon of the marks obtained by 50 students in the pre-test examination.

Overlaid Frequency Polygon: Also to compare the distributions of different data sets, frequency polygon can be used. Fig3: Overlaid Frequency polygon of the distributions of rolling two dice The observed curve overlaps expected curve.

Fig4: Overlaid cumulative frequency polygon Fig5: Frequency polygon drawn over the histogram Statistical help and online statistics help provided by us will thus help you to learn the proper use and various aspects of statistics. All Rights Reserved. By using our site, you agree to our TOS. Statistics Frequency Polygons. Class Boundaries. Cumulative frequency Less than type.

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A frequency polygon is a graphical form of representation of data. It is used to depict the shape of the data and to depict trends. It is usually drawn with the help of a histogram but can be drawn without it as well. A histogram is a series of rectangular bars with no space between them and is used to represent frequency distributions. Apr 05,  · Frequency Polygon. A frequency polygon is a graphical form of representation of data. It is used to depict the shape of the data and to depict trends. It is usually drawn with the help of a histogram but can be drawn without it as well. May 02,  · Frequency polygons are one type of graphical representation of data. There are many ways in which the data can be graphically represented and frequency polygons are the best and the most efficient of all. What are Frequency Polygons?

Your browser seems to have Javascript disabled. We're sorry, but in order to log in and use all the features of this website, you will need to enable JavaScript in your browser. Mathematics » Statistics and Probability » Histograms. A frequency polygon is sometimes used to represent the same information as in a histogram. A frequency polygon is drawn by using line segments to connect the middle of the top of each bar in the histogram.

This means that the frequency polygon connects the coordinates at the centre of each interval and the count in each interval. Connect the tops of the rectangles When we draw line segments between the tops of the rectangles in the histogram, we get the following picture:. Draw final frequency polygon Finally, we remove the histogram to show only the frequency polygon. Frequency polygons are particularly useful for comparing two data sets. Comparing two histograms would be more difficult since we would have to draw the rectangles of the two data sets on top of each other.

Because frequency polygons are just lines, they do not pose the same problem. Draw the frequency polygon for this data set using the same interval length as in the previous example. Then compare the two frequency polygons on one graph to see the differences between the distributions.

Compare frequency polygons We draw the two frequency polygons on the same axes. This is a lesson from the tutorial, Statistics and Probability and you are encouraged to log in or register , so that you can track your progress. Log In. Register or login to receive notifications when there's a reply to your comment or update on this information. Don't want to keep filling in name and email whenever you want to comment? Register or login to make commenting easier.

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Example Question Use the histogram from the previous example to draw a frequency polygon of the same data. Draw the histogram We already know that the histogram looks like this:. Frequency table We first create the table of counts for the new data set. Draw histogram and frequency polygon. Download the article for free at Siyavula. Share Thoughts. Share Thoughts Post Image. Cancel Reply. Add Math. Math Editor. Edit math using TeX:. Math preview:.

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