Education Technology

# How Close is Close?

Math: Statistics: Inferential Statistics
9-12
60 Minutes
TI-30X IIS
This is Activity 13 from the EXPLORATIONS Book:
Math Investigations with the TI-30X IIS: Activities for Secondary Mathematics

The following materials are required for this activity:
• Stopwatch
• 3 X 5 index cards
Lessons

# How Close is Close?

Activity Overview

Students compute statistical measures like the mean, standard deviation, and variance of the data set. They understand how measures of variability can be interpreted.

Before the Activity

• See the attached PDF file for detailed instructions for this activity
• Print pages 132 - 134 from the attached PDF file for your class
• During the Activity

Distribute the pages to the class.

• Start a stopwatch and stop it after 20 to 30 seconds have elapsed
• Without looking at the watch, estimate and record the elapsed time
• Compare the recorded times with the actual elapsed time
• Determine the margin of error [no negative values]
• Enter the error data in a stem and leaf plot
• Find the average error
• Determine the mean absolute deviation
• Repeat the experiment and find the new average error
• Understand that the new average error should be smaller than before due to experience in estimation
• Compute the mean of the data
• Calculate Standard Deviation and understand that it is another way of measuring the amount of variation about the mean in a data set
• Repeat the calculation with other sets of data
• After the Activity

Students complete the Student Activity pages.

• Review student results
• As a class, discuss questions that appeared to be more challenging
• Re-teach concepts as necessary