Project Overview
Student Learning Objectives
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Statistical Analyses of Variability


Time:  50 minutes

Materials:  Pencil, paper, calculator, and computers with Excel and Internet access.

Implementation:  This RWLO is recommended as a homework project but could be done in one class session. Students may discuss the steps in the activity but should individually complete all their own work.

Many students are not aware of the government’s compilation of economic data. Information regarding the Consumer Price Index (CPI) seems particularly applicable AND understandable to most students. Since details of the CPI are complex, data from several large samples are utilized. This RWLO focuses on detail work for only a single year of price changes.


  1. Discuss the extent and purpose of the data gathered by the Consumer Price Index.

  2. Review the Coefficient of Variation formula and the intended purpose of its use.

  3. Distribute and discuss the Directions for Comparing Variability and the Variability Worksheet.

  4. Instruct students to show the required calculations and answer all questions on the worksheet.

  5. One week after assigning the project, collect the worksheets and all printouts of data.

  6. Discuss the findings in class when the project is graded and returned to students.