• Open the spreadsheet to be seen by the entire class, or have individual students open it at their own computers.
• Explain that a survey has been taken to determine people's favoritie food, choosing between pizza, hotdogs, and hamburgers. The results are shown in the table.
• Two bar graphs have been made for the same data. One uses a scale from 0 to 1000, while the other goes from 950 to 1000. Do not point this difference out.
• Ask the students to study the graphs and consider the questions: Which graph do you think is better? More fair? Why?
• Have the students alter the votes in the table above to see how the data changes each graph (keep the votes between 950 and 1000). This may help them decide on the better graph. Show how a change of 10 votes in one graph seems to be very significant, but in the other is small when seen compared to all votes.
• This activity is great for discussing and illustrating misleading graphs.

Standards (Ohio Academic Content Standards):

• Math - Grade 2 - Data Analysis and Probability
  • #5 - Identify untrue or inappropriate statements about a given set of data.
• Math - Grade 4 - Data Analysis and Probability
  • #4 - Compare different representations of the same data to evaluate how well each representation shows important aspects of the data, and identify appropriate ways to display the data.
• Math - Grade 7 - Data Analysis and Probability
  • #2 - Analyze how decisions about graphing affect the graphical representation; e.g., scale, size of classes in a histogram, number of categories in a circle graph.
  • #4 - Construct opposing arguments based on analysis of the same data, using different graphical representations.
  • #6 - Identify misuses of statistical data in articles, advertisements, and other media.
• Math - Grade 9 - Data Analysis and Probability
  • #4 - Describe and compare various types of studies (survey, observation, experiment), and identify possible misuses of statistical data.