Histograms in Statistics Explained

Before we get into the details of histograms, can you think which graph or representation would be useful if you were to represent data concentration or the group or interval that has the majority of the data points? 

For a case like the one above, histograms can be useful. Histograms are a special type of bar chart with no spaces in between the bars and whose x-axis is divided into intervals. Each interval in a histogram represents an interval or a group in the data set, and each bar represents the concentration of the data points in that interval. 

You will learn more about histograms in the forthcoming video.

In the video above, you learnt that a histogram is a visual representation of the distribution of data. The data can be both numerical and categorical. There are two important points to keep in mind about histograms. These include the following:

• A histogram is an extended form of a bar graph, and there are no gaps between adjacent bars in a histogram.

• To construct a histogram, you need to first construct a frequency distribution table.

In the upcoming video, you will learn how to construct histograms in Excel. The data set used is that of the Portuguese bank.

In the video, you saw that it is simpler to visualise and comment upon the distribution of grouped data using histograms. 

Now, in the next video, you will learn about a variety of applications of histograms, which are illustrated through a few more examples.

So, in the video, you learnt how the applicability of histograms can be extended to different use cases that deal with intervals. Specifically, you saw how histograms were useful for finding the:

1. Age range of the majority of the employees in the example company, and 

2. The time slot in which the maximum number of employees in an example company reached the office.

You also learnt what a normal distribution looks like. In a normal distribution, most of the values are concentrated around the central peak, and the concentration of values decreases equally as one moves from the peak towards either the left or the right side of the distribution. You will learn more about normal distribution in upcoming sessions. 

Additional Learning 

1. Here is an article by SPSS tutorials explaining the utility of histograms 
2. You can refer to the links below to learn how to create frequency tables: 

   1. Creating a frequency table

   2. Creating a frequency table in Excel