Calculate quartiles (Q1, Q2, Q3), interquartile range (IQR), and five-number summary with box plot visualization. Detect outliers and analyze data distribution.
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Calculate quartiles (Q1, Q2, Q3), interquartile range (IQR), and five-number summary for any dataset. Visualize your data distribution with an interactive box plot, detect potential outliers, and understand how your data is spread across percentiles.
Quartiles are values that divide a sorted dataset into four equal parts. Q1 (25th percentile) separates the lowest 25% of data, Q2 (50th percentile) is the median, and Q3 (75th percentile) separates the lowest 75% of data. The Interquartile Range (IQR = Q3 - Q1) measures the spread of the middle 50% of data and is used to identify outliers.
IQR Formula
IQR = Q₃ - Q₁Summarize datasets with five-number summaries and identify the central tendency and spread of data.
Detect unusual measurements in manufacturing by identifying values outside the interquartile range.
Report data distributions in research papers using box plots based on quartile calculations.
Analyze salary distributions, market data, and investment returns by understanding quartile breakdowns.
The Exclusive method (TI-83 style) excludes the median from both halves when calculating Q1 and Q3 for odd-sized datasets. The Inclusive method (Tukey's hinges) includes the median in both halves. Both give identical results for even-sized datasets.