When we have histograms of different shapes, how can we use one number to describe the data?

Negatively Skewed   Normal Distribution         Positively Skewed

“Skewed to the Left”           Symmetric     “Skewed to the Right”

Mode

One method could be the mode, the value in the dataset that occurs the most. Since histograms are composed of bins, however, the mode would be a range of values. Try matching the following modes with the correct histogram:

Mode 1: 20-25

Mode 2: 110-120

Mode 3: 150-160

Mode 1 belongs to the positively skewed distribution; Mode 2 to the negatively skewed distribution; and Mode 3 to the normal distribution.

As the bin size decreases, the mode becomes more exact; as the bin size increases, the mode becomes more ambiguous. In non-uniform datasets, values are grouped around a particular area. This is where you see the hump of the distribution. For example, take the following dataset, visualized with a dot plot.

A histogram of this data with bin size 5 looks like this:

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## 2 thoughts on “Lesson 3: Central Tendency”

1. Paula Poblete says:

Hi! where is lesson 3? Thanks! 📊

1. Hi Paula! Sorry for the delay. The formatting got messed up with a new version of WordPress, so I had to re-create the preview. You should see it now!