Outlier Effects on Mean and Range

8th Gradeβ€’20 minutesβ€’CCSS 8.SP.A.1

Learning Objective

I can describe how outliers affect the mean and range of a data set.

Key Concepts

The mean uses all of the data in a set, but it is easily influenced by outliers.

The median is the middle value in a sorted data set, and it is the best measure of central tendency to report when there are outliers.

The mode is the value that occurs most frequently, but it is not robust because small changes in frequency can easily affect it.

Practice Questions

This lesson includes 3 practice questions to reinforce learning.

View questions preview

1. Explain how an outlier affects the mean of a data set.

2. Why is the median often a better measure of central tendency than the mean when outliers are present in a data set?

3. Which of the following statements is true regarding the effect of outliers on measures of central tendency?

Educational Video

What to Report When There is an Outlier - Measures of Central Tendency

ProfKelley

Create Your Own Lesson

Generate a custom lesson plan like this one in minutes with Insta~Lesson