decile
{{Short description|Quantile dividing data into 10 equal parts}}
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.{{citation|title=Introduction to Statistics and Data Analysis: For the Behavioral Sciences|first=Robert S.|last=Lockhart|publisher=Macmillan|year=1998|isbn=9780716729747|page=78|url=https://books.google.com/books?id=93pxNPtt0coC&pg=PA78}}. A decile is one possible form of a quantile; others include the quartile and percentile.{{citation|title=Handbook of Parametric and Nonparametric Statistical Procedures|first=David J.|last=Sheskin|edition=3rd|publisher=CRC Press|year=2003|isbn=9781420036268|page=10|url=https://books.google.com/books?id=bmwhcJqq01cC&pg=PA10}}. 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.
Special usage: The 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 to ( = 10th percentile, = 20th percentile and so on). It is calculated as follows:{{cite journal
| first1 = Sohel
| last1 = Rana
| first2 = Md.
| last2 = Siraj-Ud-Doulah
| first3 = Habshah
| last3 = Midi
| first4 = A. H. M. Rahmatullah
| last4 = Imon
| title = Decile mean: A new robust measure of central tendency
| journal = Chiang Mai Journal of Science
| volume = 39 |issue = 3 |pages = 478–485
| date = 2012
| url= https://www.thaiscience.info/journals/Article/CMJS/10905266.pdf
}}
:
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.{{cite journal
| first1 = Md.
| last1 = Siraj-Ud-Doulah
| title = An Alternative Measures of Moments Skewness Kurtosis and JB Test of Normality
| journal = Journal of Statistical Theory and Applications
| volume = 20 |issue = 2 |pages = 219–227
| date = 2021
| doi = 10.2991/jsta.d.210525.002
| doi-access = free
}}
See also
- Summary statistics
- Socio-economic decile (for New Zealand schools)