Measures of centre give a typical value for a set of data. Measures of spread tell us how the data differ from each other. To complete the picture of a quantitative variable we need to know the shape of the distribution of its values. Is there symmetry around a common value? Are large values more common than small values? Is there none, or more than one, peak?
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Notes on the video: The Shape of the Data
A point to consider for this video:
For small data sets, a dot plot is an alternative to a histogram. Rather than grouping the data in bins, a dot plot shows a dot for each data value, over a horizontal axis spanning the range of the data. Below are a histogram and a dot plot for the life expectancy (years) of 197 countries. Do the features of the shape appear similar in the two plots?