http://www.ck12.org Chapter 8. Organizing and Displaying Data for Comparison
Both the academic and advanced math marks went up and down over the past 4 years. If Mrs. Smith looks at the
difference between 2007 and 2010, she can see that there is an improvement in the final grades for her students.
Although there are many factors that can affect these grades, she can say that the change in her instruction is making
some difference in the results for her students. Other factors might have contributed to the huge decline in grades
for the academic math students in 2009. You can make this conclusion for Mrs. Smith, as there was a marked
improvement in her advanced math course. In 2009, it seemed her instruction methods were working well with the
advanced students, but other factors were affecting the academic students.
Example C
Robbie is in charge of the student organization for new food selections in the cafeteria. He designed a survey to
determine if 4 new food options would be good to put on the menu. The results are shown below:
TABLE8.5:
Food Option Yes votes No votes
Fish burgers 10 5
Vegetarian pizza 7 18
Brown rice 23 9
Carrot soup 20 20Draw a double bar graph to represent the data, and draw any conclusions that you can from the resulting chart.
The double bar graph is as follows: