kb/data/en.wikipedia.org/wiki/Decile-0.md

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Decile 1/1 https://en.wikipedia.org/wiki/Decile reference science, encyclopedia 2026-05-05T12:22:20.766128+00:00 kb-cron

In descriptive statistics, a decile is any of the nine values that divide the sorted data into ten equal parts, so that each part represents 1/10 of the sample or population. A decile is one possible form of a quantile; others include the quartile and percentile. A decile rank arranges the data in order from lowest to highest and is done on a scale of one to ten where each successive number corresponds to an increase of 10 percentage points.

== Decile mean == A moderately robust measure of central tendency, known as the decile mean, can be computed by making use of a sample's deciles

      D
      
        1
      
    
  

{\displaystyle D_{1}}

to

      D
      
        9
      
    
  

{\displaystyle D_{9}}

(

      D
      
        1
      
    
  

{\displaystyle D_{1}}

= 10th percentile,

      D
      
        2
      
    
  

{\displaystyle D_{2}}

= 20th percentile and so on). It is calculated as follows:

    D
    M
    =
    
      
        
          
            ∑
            
              i
              =
              1
            
            
              9
            
          
          
            D
            
              i
            
          
        
        9
      
    
  

{\displaystyle DM={\frac {\sum _{i=1}^{9}D_{i}}{9}}}

Apart from serving as an alternative for the mean and the truncated mean, it also forms the basis for robust measures of skewness and kurtosis, and even a normality test.

== See also == Summary statistics Socio-economic decile (for New Zealand schools)

== References ==