Compare an Arithmetic Mean with a Median
A mean divides the total by the number of values.
About 20 minutes, plus any extended practice
Open lesson 1Algebra1: Descriptive Data and Outliers
Data summaries describe center and spread using stated definitions. Mean, median, interquartile range and mean absolute deviation respond differently to extreme values, so the chosen measure should match the question and convention.
Before you begin
- Order numbers; compute a mean; take absolute differences.
Choose by skill rather than age alone. Read with an adult when useful, revisit a lesson, or explore another grade.
Follow the lesson sequence
Apply a Stated Quartile Convention
Interquartile range subtracts the lower quartile from the upper quartile.
About 20 minutes, plus any extended practice
Open lesson 2Average Absolute Distances from the Mean
Mean absolute deviation averages each value’s nonnegative distance from the mean.
About 20 minutes, plus any extended practice
Open lesson 3Separate Changes in Mean and Median
Replacing one endpoint of a sorted data set can increase the total without changing the middle value.
About 20 minutes, plus any extended practice
Open lesson 4Review and transfer
After the lessons, try 4 new review cases and a practical task. Each answer has an explanation and a link back to the related lesson.
Open the unit reviewGuest answers are temporary. Keep your own paper or document; this unit does not certify completion or record a school grade.
Topic references
- California CCSS mathematics topic reference: topic reference — Algebra1: Descriptive Data and Outliers
These references informed the topic selection. They do not certify complete standards alignment.