Types of Histogram

The words used to describe the patterns in a histogram are: "symmetric", "skewed left" or "right", "unimodal", "bimodal" or "multimodal".

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  Symmetric, unimodal
  
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  Skewed right
  
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  Skewed left
  
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  Bimodal
  
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  Multimodal
  
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  Symmetric
  

It is a good idea to plot the data using several different bin widths to learn more about it. Here is an example on tips given in a restaurant.

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  Tips using a $1 bin width, skewed right, unimodal
  
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  Tips using a 10c bin width, still skewed right, multimodal with modes at $ and 50c amounts, indicates rounding, also some outliers
  

Here are a couple more examples:

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  Prices of houses sold in Ames in 2009 exhibits some right skew
  
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  Aces by players in a grand slam tennis tournament, facetted by gender. There are more