quartile n : (statistics) any of three points that divide an ordered distribution into four parts each containing one quarter of the scores
Nounquartile (plural quartiles)
any of the three points
- Czech: kvartil
In descriptive statistics, a quartile is any of the three values which divide the sorted data set into four equal parts, so that each part represents 1/4th of the sampled population.
The difference between the upper and lower quartiles is called the interquartile range.
There is no universal agreement on choosing the quartile values.http://www.robhyndman.info/papers/quantile.htm One possible rule (employed by the TI-83 calculator boxplot and 1-Var Stats functions) is as follows:
- Use the median to divide the ordered data set into two halves. Do not include the median into the halves.
- The lower quartile value is the median of the lower half of the data. The upper quartile value is the median of the upper half of the data.
The examples below assume this rule. Another possible rule would be to include the median in the halves when calculating the quartiles. This would give significantly different answers to the examples.
Example 1 Data Set: 6, 47, 49, 15, 42, 41, 7, 39, 43, 40, 36 Ordered Data Set: 6, 7, 15, 36, 39, 40, 41, 42, 43, 47, 49
\begin Q_1 = 15 \\ Q_2 = 40 \\ Q_3 = 43 \end
Example 2 Ordered Data Set: 7, 15, 36, 39, 40, 41
\begin Q_1 = 15 \\ Q_2 = 37.5 \\ Q_3 = 40 \end
Example 3 Ordered Data Set: 1 2 3 4
\begin Q_1 = 1.5 \\ Q_2 = 2.5 \\ Q_3 = 3.5 \end
quartile in Danish: Kvartil
quartile in German: Quartil
quartile in Spanish: Cuartil
quartile in Persian: چارک (آمار)
quartile in French: Quartile
quartile in Italian: Quartile
quartile in Japanese: 分位数
quartile in Dutch: Kwartiel
quartile in Polish: Kwartyl
quartile in Portuguese: Quartil
quartile in Swedish: Kvartil
quartile in Turkish: Dörttebirlik