Education Technology

Confidence Intervals

Published on 06/09/2008

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.

    Follow the Activity procedures:

  • 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