Lesson plan

Lesson 10: The Effect of Extremes

teaches Common Core State Standards MP4 http://corestandards.org/Math/Practice/MP4
teaches Common Core State Standards MP7 http://corestandards.org/Math/Practice/MP7
teaches Common Core State Standards MP5 http://corestandards.org/Math/Practice/MP5
teaches Common Core State Standards HSS-ID.A.3 http://corestandards.org/Math/Content/HSS/ID/A/3
teaches Common Core State Standards HSS-ID.A.1 http://corestandards.org/Math/Content/HSS/ID/A/1
teaches Common Core State Standards HSS-ID.A.2 http://corestandards.org/Math/Content/HSS/ID/A/2

Lesson 10: The Effect of Extremes

The mathematical purpose of this lesson is to recognize a relationship between the shape of a distribution and the mean and median. Students will use dot plots to investigate this relationship. Earlier in this unit, students created data displays so that the shape of the distribution is clear. This lesson connects to upcoming work because students will use the shape of the distribution and measures of center to make decisions about how to summarize data.

In this lesson, students begin by using aspects of mathematical modeling (MP4) to select appropriate variables to compare. In another activity, students make use of structure (MP7) and appropriate tools (MP5) to construct dot plots of data that have prescribed measures of center.

One of the activities in this lesson works best when each student has access to technology that will easily compute measures of center to produce dot plots or histograms because it will help students focus on understanding the relationship between extreme values and the measure of center without distracting with lengthy computations.

Lesson overview

  • 10.1 Warm-up: Battle Royale (5 minutes)
  • 10.2 Activity: Separated by Skew (15 minutes)
    • There is a digital applet in this activity.
  • 10.3 Activity: Plots Matching Measures (10 minutes)
    • Includes "Are you Ready for More?" extension problem
  • Lesson Synthesis
  • 10.4 Cool-down: Shape and Statistics (5 minutes) 

Learning goals:

  • Recognize the relationship between mean and median based on the shape of the distribution.
  • Understand the effects of extreme values on measures of center.

Learning goals (student facing):

  • Let’s see how statistics change with the data.

Learning targets (student facing):

  • I can describe how an extreme value will affect the mean and median.
  • I can use the shape of a distribution to compare the mean and median.

Required materials:

  • Internet-enabled device

Required preparation:

  • Acquire devices that can run GeoGebra (recommended) or other spreadsheet technology.
  • It is ideal if each student has their own device. (A GeoGebra Spreadsheet is available under Math Tools.)
  • Internet-enabled devices are required for the digital version of the activity Separated by Skew.


  • This lesson builds on the standard: CCSS.HSS-ID.A.1MS.S-ID.1MO.A1.DS.A.1
  • This lesson builds towards the standard: CCSS.HSS-ID.A.3MS.S-ID.3MO.A1.DS.A.3






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