Fundamentals of Statistics contains material of various lectures and courses of H. Lohninger on statistics, data analysis and chemometrics......click here for more. 
Home Univariate Data Measures of Location Quartile  
See also: Median, Interquartile Range, Quantiles  
QuartileQuartiles partition  as the name suggests  the corresponding distribution into four quarters each containing 25% of the data. A particular quartile is therefore the border between two neighboring quarters of the distribution.
The calculation of the quartiles is sometimes not quite clear (especially if the number of observations of a sample is not divisible by four). We therefore provide exact instructions how to calculate the quartiles. Assuming a sample of N observations the quartiles are defined as follows ("round" stands for the rounding to the nearest integer):
Remark on practical aspects: quartiles are usually calculated only for samples with more than 12 observations (a minimum of 20 observations would be even better).


Home Univariate Data Measures of Location Quartile 
Last Update: 20121008