Free Printable Five Number Summary Worksheets for Class 9

In 9th-grade Algebra 1 or an introductory statistics course, the five-number summary is treated as a foundational tool for formally describing data distributions. It is used to calculate the interquartile range (IQR) and apply the 1.5xIQR rule to mathematically identify outliers.

Frame it as one of several tools for data analysis. Teach students to compare the five-number summary (which is resistant to outliers) with measures like mean and standard deviation (which are sensitive to outliers). Discuss when to use each set of measures to best describe a data set, particularly in the context of skewed versus symmetric data.

Beyond simple calculation errors, high school students often misinterpret the meaning of quartiles. For example, they might think Q1 represents 25% of the maximum value, rather than the value below which 25% of the data points fall. They may also struggle to correctly apply the formula to identify outliers.

This topic aligns with the Common Core's high school statistics and probability standards (S-ID), which focus on summarizing, representing, and interpreting data. Specifically, calculating the five-number summary is a prerequisite for representing data with box plots (S-ID.A.1) and comparing center and spread for different data sets (S-ID.A.2).

Effective practice at this level involves multi-step analysis. Worksheets should include problems where students must calculate the five-number summary, determine the interquartile range, formally test for outliers, and write a concise paragraph describing the data's distribution based on their findings.

Use this worksheet for targeted practice or as a formative assessment to check for understanding. It can be assigned as a digital activity on Wayground or printed as a PDF for in-class work or homework. A full answer key is included to facilitate quick grading or student self-assessment.