ALEX Learning Activity


Is This Normal? Extending the Normal Distribution

A Learning Activity is a strategy a teacher chooses to actively engage students in learning a concept or skill using a digital tool/resource.

You may save this Learning Activity to your hard drive as an .html file by selecting “File”,then “Save As” from your browser’s pull down menu. The file name extension must be .html.
  This learning activity provided by:  
Author: Lorie White
System:Lauderdale County
School:Rogers High School
  General Activity Information  
Activity ID: 2603
Is This Normal? Extending the Normal Distribution
Digital Tool/Resource:
Is This Normal? Extend - Desmos Activity
Web Address – URL:

Students will work through a Desmos activity on Normal Distribution. They will be reminded of how to find the mean and standard deviation of a data set. Students will practice doing both calculations. Next, using the mean and standard deviation they will define the intervals in a normal curve and will approximate the percentage of items in each interval using the Empirical Rule.

This activity results from the ALEX Resource Development Summit.

  Associated Standards and Objectives  
Content Standard(s):
MA2015 (2016)
Grade: 9-12
41 ) Use the mean and standard deviation of a data set to fit it to a normal distribution and to estimate population percentages. Recognize that there are data sets for which such a procedure is not appropriate. Use calculators, spreadsheets, and tables to estimate areas under the normal curve. [S-ID4]

Learning Objectives:

Students will be able to:

  • find the mean of a data set.
  • find the standard deviation of a data set.
  • use the mean and standard deviation to define the intervals in a normal distribution.
  • use the empirical rule to approximate the area under the normal distribution.
  Strategies, Preparations and Variations  

  1. Direct each student to the Desmos learning activity, Is It Normal? Extend.
  2. Instruct the students to follow and answer the prompts provided in the activity. (There are teaching prompts and sample responses at the bottom of the activity.)
  3. Circulate while students are working and assist with any questions or problems they might encounter.
  4. The teacher can monitor students' progress on Desmos to identify problems or gaps in learning.
  5. If the majority of students struggle with a common topic, pause the activity, and address the misconception.
Assessment Strategies:

The teacher can assess the students' answers in Desmos for assessment purposes. The teacher should correct the students' mistakes or misunderstandings.

Advanced Preparation:

The teacher will need to ensure the classroom has the following:

  1. internet connection (WiFi).
  2. classroom set of computers, iPads, or smart devices. (If allowed students can use their own personal devices.)

Prior to the lesson, the teacher will need to assign Is It Normal? Extend through Google Classroom or another online learning platform. 

Prior to the lesson, the teacher should be familiar with Desmos and should create a free class code for the activity. If the teacher does not have a Desmos account, he/she will need to create a free Desmos account. 

The teacher should work through the problems and be familiar with possible student responses. (Teaching prompts and sample responses at the bottom fo the activity.)

Optional:  Prepare a copy of the normal curve with percentages for each student to use. (This copy has 3 curves per page)

Variation Tips (optional):

Students could work in pairs to complete this activity. If students do not have access to a device, the activity could be done as a whole group activity. If using with a whole group, the teacher should have students write their answers on whiteboards or on paper and check for mistakes. 

Notes or Recommendations (optional):

ALCOS 2019

Algebra II/Statistics

25. From a normal distribution, use technology to find the mean and standard deviation and estimate population percentages by applying the empirical rule.
a. Use technology to determine if a given set of data is normal by applying the empirical rule.
b. Estimate areas under a normal curve to solve problems in context, using calculators, spreadsheets, and tables as appropriate.

  Keywords and Search Tags  
Keywords and Search Tags: Bell Shaped Curve, Empirical Rule, Mean, Normal Distribution, Standard Deviation