Quartiles split a ranked data set into four equal parts. The first quartile (Qβ) marks the 25th percentile, the second quartile (Qβ) is the median, and the third quartile (Qβ) indicates the 75th percentile, giving insight into the upper spread of the data.
The third quartile is defined as the value that separates the highest 25β―% of observations from the rest. When the data are ordered from smallest to largest, Qβ can be located at the (frac{3(n+1)}{4})βth position, where (n) is the number of data points. If this position is not an integer, linear interpolation between the surrounding values is used.
Knowing Qβ helps analysts understand the upper tail of a distribution, detect outliers, and compare data sets. It is widely used in descriptive statistics, boxβplot construction, and performance benchmarking.
What is the third quartile in statistics?
How do I calculate the third quartile manually?
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What if my data set has an even number of observations?
Results are for informational purposes only and do not constitute professional advice.
