Five Number Summary

Statistics · Axiom Academy

Understanding data distribution through five key values The five number summary provides a complete snapshot of a dataset's distribution using just five key values: the minimum, first quartile (Q1), median, second quartile (Q2), third quartile (Q3), and maximum. These five numbers tell us where the data starts, where it ends, and how it's spread out in between. Let's explore how to find each component step by step! Let's work with this dataset of test scores: 78, 92, 65, 88, 74, 95, 82, 70, 85, 90, 68 2 Find the Minimum and Maximum With 11 values, the median is the 6th value (middle position). 4 Find the First and Third Quartiles Lower half: 65, 68, 70, 74, 78 → Q1 = 70 (middle value) Upper half: 85, 88, 90, 92, 95 → Q3 = 90 (middle value) 5 The Complete Five Number Summary What this tells us: The middle 50% of test scores fall between 70 and 90, with a median score of 82. The scores range from 65 to 95, showing moderate spread with the data slightly concentrated in the upper range.

This is the written version of the interactive lesson above. See the full Statistics course.