When do we use frequency polygons

A frequency polygon for psychology test scores shown in Figure 1 was constructed from the frequency table shown in Table 1. The first label on the X-axis is This represents an interval extending from Since the lowest test score is 46, this interval has a frequency of 0. The point labeled 45 represents the interval from There are three scores in this interval.

There are scores in the interval that surrounds You can easily discern the shape of the distribution from Figure 1. Most of the scores are between 65 and It is clear that the distribution is not symmetric inasmuch as good scores to the right trail off more gradually than poor scores to the left.

In the terminology of Chapter 3 where we will study shapes of distributions more systematically , the distribution is skewed. Figure 1. Frequency polygon for the psychology test scores. We hope this detailed article helps you. If you have any doubt regarding this article, you can drop your comments below.

We will get back to you at the earliest. Support: support embibe. General: info embibe. Skip to primary navigation Skip to main content Skip to primary sidebar K12 K What is frequency polygon? The points on the graph are typically connected by straight lines in the order in which they occur.

The following data shows the Annual Consumer Price Index, each month, for ten years. Construct a time series graph for the Annual Consumer Price Index data only. The following table is a portion of a data set from www. Use the table to construct a time series graph for CO 2 emissions for the United States. Time series graphs are important tools in various applications of statistics.

When recording values of the same variable over an extended period of time, sometimes it is difficult to discern any trend or pattern. However, once the same data points are displayed graphically, some features jump out. Time series graphs make trends easy to spot. Pearson Education, Gunst, Richard, Robert Mason. CRC Press: A histogram is a graphic version of a frequency distribution.

The graph consists of bars of equal width drawn adjacent to each other. The horizontal scale represents classes of quantitative data values and the vertical scale represents frequencies.

The heights of the bars correspond to frequency values. Histograms are typically used for large, continuous, quantitative data sets.

A frequency polygon can also be used when graphing large data sets with data points that repeat. The data usually goes on y -axis with the frequency being graphed on the x -axis. Time series graphs can be helpful when looking at large amounts of data for one variable over a period of time. Sixty-five randomly selected car salespersons were asked the number of cars they generally sell in one week.

Fourteen people answered that they generally sell three cars; nineteen generally sell four cars; twelve generally sell five cars; nine generally sell six cars; eleven generally sell seven cars. Complete the table. What does the frequency column in Figure sum to? What does the relative frequency column in Figure sum to? What is the difference between relative frequency and frequency for each data value in Figure?

The relative frequency shows the proportion of data points that have each value. The frequency tells the number of data points that have each value. What is the difference between cumulative relative frequency and relative frequency for each data value? To construct the histogram for the data in Figure , determine appropriate minimum and maximum x and y values and the scaling.

Sketch the histogram. Label the horizontal and vertical axes with words. Include numerical scaling. Construct a frequency polygon from the frequency distribution for the 50 highest ranked countries for depth of hunger. Find the midpoint for each class. These will be graphed on the x -axis. The frequency values will be graphed on the y -axis values. Use the two frequency tables to compare the life expectancy of men and women from 20 randomly selected countries.

Include an overlayed frequency polygon and discuss the shapes of the distributions, the center, the spread, and any outliers. What can we conclude about the life expectancy of women compared to men? Construct a times series graph for a the number of male births, b the number of female births, and c the total number of births.

The following data sets list full time police per , citizens along with homicides per , citizens for the city of Detroit, Michigan during the period from to Suppose that three book publishers were interested in the number of fiction paperbacks adult consumers purchase per month. Each publisher conducted a survey. In the survey, adult consumers were asked the number of fiction paperbacks they had purchased the previous month.

The results are as follows:. Often, cruise ships conduct all on-board transactions, with the exception of gambling, on a cashless basis. At the end of the cruise, guests pay one bill that covers all onboard transactions.

Suppose that 60 single travelers and 70 couples were surveyed as to their on-board bills for a seven-day cruise from Los Angeles to the Mexican Riviera. Following is a summary of the bills for each group. Twenty-five randomly selected students were asked the number of movies they watched the previous week.

The results are as follows. Use the following information to answer the next two exercises: Suppose one hundred eleven people who shopped in a special t-shirt store were asked the number of t-shirts they own costing more than? The percentage of people who own at most three t-shirts costing more than? If the data were collected by asking the first people who entered the store, then the type of sampling is:. Construct a bar graph of obesity rates of your state and the four states closest to your state.

Hint: Label the x -axis with the states. Skip to content Descriptive Statistics. Therefore, people have decided to represent the data in the form of pictures. This is one of the best methods but the major disadvantage is that pictures are going to consume a lot of time and the entire idea is going to take a lot of effort.

Sheets: This representation of data wherever possible is one the best methods as the data can be retrieved easily. There is one major drawback with this form. All the data is in a clustered form and it is very difficult for the people to see to it that they are going to segregate the data. Graphical Representation: This is found to be one of the best forms of representation of data.

This is used widely by many people all over the world. This is one the most efficient methods of representation as such. 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? The data that is present on a sheet of paper in the form of tables is sorted out and made into such a way that it can be plotted on a graph paper.

This is going to be very much useful for the people who are reading the data. The graph so plotted is also represented in the form of bars so that it is clearer for the people to understand the statistics as such.

All this help to understand the frequency distribution of the data in a much better way. What are the Advantages of the Frequency Polygons?