Introduction

A histogram is defined by Minitab as follows:

A histogram is a graph that you can use to assess the shape and spread of continuous sample data. You might create a histogram before or during an analysis to help confirm assumptions and guide additional analyses.

http://support.minitab.com/en-us/minitab/17/topic-library/basic-statistics-and-graphs/graphs/graphs-of-distributions/histograms/histogram/

A histogram can look like this:

The features of a histogram include

  • The horizontal axis is made up of bins of class intervals
  • The vertical axis comprises frequencies
  • The bars of a histogram are always shown without gaps between them

A histogram can help us to see whether data are

  • Normally distributed
  • Skewed left or right
  • Tall or short
  • Spread wide or narrowly

The histogram above is exactly the kind of histogram that this page is concerned with although there are variations on this graph.

Downloads: download the following two files to explore this page in full and to see just how I created five histograms in five different ways!

 

The PDF file of the full version of this page: five_ways_histogram

The Excel file for the examples discussed here: five_ways_histogram … this file uses random numbers to create the raw data so what you see here will be different from what you see there. You will also notice that you need to increase the height of row 19 to see the sparkline in all its glory!

 

Duncan Williamson

7th May 2017

 

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