Pie Chart (Circle Graph) By: Matt Davidson Peter Ditzler Lukas Noller Period 5 Max Stauffer Due: 2/14/13

Definition A circular graph that is divided into sections that represent data in ratios such as percentages. Best visual representation for a graph if you are showing statistics. It is mainly used in representing statistics. Requires 1 set of data with frequencies

Example of the Graph In this situation the graph is representing people’s main preference for renewable/carbon neutral sources of energy.

How to Create a Pie Chart To create a pie chart, you must collect your data first. When you have collected your data, take a recorded statistic and divide that number by the total number of statistics, to get a percent. You must do that with all of your statistics. Then, create a circle and divide it up into sections, according to the percent sizes. Make sure you label each section what it represents, or have a key. You can even write the percentages as well on each section.

Pie Chart Created Using Collected Data Problem Based On the Graph Peter sees the trend in the pie chart to the left. He is trying to predict the amount of people that likes each channel in Mrs. Yost’s period 2 class. If Mrs. Yost has 45 people in her period 2 class, rounded to the nearest person, predict the amount of kids that watch each channel. (You may use a calculator.) There was a total of 58 votes

How to Solve the Problem If you look at the percentages of favoritism of each show, you can see that FOX has the lowest amount of votes, 5%, NBC has 10%, Comedy Central has 11%, CBS has 19%, ABC Family has 26%, and ESPN has 29% of the votes. Now, if you want to find the percentages in a class of 45 kids, and the graph followed a trend, you would multiply 45 by each percent in its decimal form. Ignore that the original poll had 58 votes. You would multiply 45 by 0.05 for FOX’s percentage of votes, by 0.1 for NBC’s percentage of votes, and so on. Remember to round your percentages to the nearest whole number Answers: FOX: 2% NBC: 5% Comedy Central: 5% CBS: 9% ABC Family 12% ESPN: 13% These are rounded percentages, so they don’t add up to 45 exactly

Advantages/Disadvantages Gives audience the best visual for statistics. You can understand it with little knowledge of math. It can summarize a large set of data with minimal explanation. Easier to understand than other graphs and easier to set up. Disadvantages A pie chart can only have one set of data. It is hard to tell which sections are bigger. You can only use it for expressing data out of a whole. It does not tell you how large the whole is. (There is no numerical data.) If you have too many sections divided on the chart it becomes crowded.

A Pie Chart That is Difficult to Understand There are too many sectors to get information easily. Some sectors are also very hard to see because of their size. Some colors are also repeated, or are very similar to get mixed up when trying to interpret the data.

Bibliography. http://thephoenixsun.com/archives/6954 Picture for example. http://en.wikipedia.org/wiki/Pie_chart Information (Overall) http://en.wikipedia.org/wiki/File:Piecharts.svg Disadvantage Photo http://www.ehow.com/list_6715678_advantages-disadvantages- pie-chart.html Information on advantages and disadvantages. http://broccoliandchocolate.com/2010/11/ Picture for slide 6 s684.photobucket.com Advantage Photo