# Activities

• • • ##### Subject Area

• Math: Statistics: Displaying and Describing Univariate Data

• ##### Author 9-12

45 Minutes

• ##### Device
• TI-Nspire™ CX/CX II
• TI-Nspire™ CX CAS/CX II CAS
• TI-Nspire™ Navigator™
• TI-Nspire™
• TI-Nspire™ CAS
• ##### Software

TI-Nspire™
TI-Nspire™ CAS

3.0

• ##### Report an Issue

SD: How Far is Typical?

#### Activity Overview

This lesson involves gaining a basic understanding of what standard deviation is measuring by examining the location of data around the mean.

#### Objectives

• Students will identify the standard deviation as a measure of spread about the mean of a distribution and loosely interpret it as an "average" or typical distance from the mean.

#### Vocabulary

• deviation
• dotplot
• mean
• range
• residual
• standard deviation

#### About the Lesson

This lesson involves gaining a basic understanding of what standard deviation is measuring by examining the location of data around the mean.

As a result, students will:

• Find the sum of the residuals to be 0 and consider both squaring and absolute value to eliminate the negative values.
• Compare the standard deviation to the mean of the absolute values of the residuals as the data changes.
• Change the amount of snowfall by moving data points and comparing the squared standard deviation and the mean of the squared residuals in the plots.