Education Technology

# Activities

• ##### Subject Area

• Math: Statistics: Inferential Statistics

9-12

60 Minutes

• ##### Device
• TI-89 / TI-89 Titanium

TI Connect™

• ##### Accessories

TI Connectivity Cable

• ##### Other Materials
This is Activity 11 from the EXPLORATIONS Book:
Advanced Placement Statistics with the TI-89

## Confidence Intervals

#### Activity Overview

Students understand the confidence intervals for a proportion and for a mean. They also examine the confidence intervals for the difference between two means, and for the difference between two proportions.

#### Before the Activity

Install the Statistics with List Editor application on the calculator using one of these two methods:

• TI Connect™, a TI Connectivity Cable, and the Unit-to-Unit Link Cable
• TI-Navigator™  "send to class" feature
• See the attached PDF file for detailed instructions for this activity
• Print pages 137 - 148 from the attached PDF file for your class
• #### During the Activity

Distribute the pages to your class.

• Enter, for a population, the number of successes, sample size, and the confidence level
• View the confidence interval and study the margin of error
• Enter functions to generate the number of successes for a given sample size, to determine the confidence interval, and to display results
• Observe that the results include the population value in the confidence interval for a proportion

• Enter another data set as a list
• Calculate a 'z' interval, if the standard deviation is known
• Calculate a 't' interval, if the standard deviation is not known
• Determine, by both methods, the confidence interval for a mean, and the margin of error
• Note that both techniques give the same result

• Determine Large Sample Confidence Intervals for the difference between two proportions and difference between two means
• #### After the Activity

Review student results:

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