GRAPHS! GRAPHS! GRAPHS! 8 TH Grade Science Schindewolf Intermediate School

Graphs are “pictures” of data. Graphs allow people to present and view data in a format that is easier to see and make interpretations.

There are several types of graphs but the three we are going to focus on today are…

Circle graphs are graphs in the shape of a circle. They are sometimes called “Pie Graphs” or “Pie charts”. Often Circle Graphs are divided into different parts and each part is color coded. Consider this chart that shows how a college student’s money is spent… Q?#1 What takes the largest percentage of money? Q?#2 Which category is taking 10% of the money?

When do I use a Circle graph? Any time you have percents %, Any time you are comparing things and you have ALL of the possible data. Consider the chart to the right that shows a class of 8 th grader’s music preferences… Q?#3 What is the LEAST popular type of music? Q?#How many MORE students preferred Jazz to Rap?

Bar Graphs are usually considered the “easiest” type of graph to read. They include solid lines or “bars” to represent different categories of data. Bar Graphs can be horizontal but are usually oriented vertical with categories across the bottom.

When do I use a Bar graph? Whenever you are comparing information that can be placed in different categories. Q?#5 What correlation do you see between highest level of education and % Unemployment?

How do you know when to use a Bar Graph vs. a Circle graph? If you have ALL of the possible information-you can use a circle. If you have only some of the information you must use a bar graph. For example, imagine you wanted to compare favorite types of fruit. If you asked 10 kids in a class of 30, you would use a bar graph. If you asked all 30, you could use a circle graph!

Line Graphs are a special kind of graphs where a single line compares two variables. Often line graphs can display two separate lines for two different categories of information.

When do I use a Line graph? Any time you are comparing a single type of variable with another variable. Any time you are showing change over time. Q? #6 What was Trey’s height in inches at 4 years of age? Q?#7 How many inches did Trey grow from Birth to age 8?

Variables… Does it matter what goes where?? YES! In line and bar graphs, the Dependent Variable ALWAYS goes on the Y axis. Remember DRY? The Independent Variable ALWAYS goes on the X axis. Remember MIX Y X

8. What type of graphs should you use if showing measurement over time? (See slide 9) 9. What axis does the Independent Variable belong on?

10. If you have data showing average attendance for 5 different schools in a district of 17 schools, What kind of graph would you use? 11. If you have data showing average attendance for all 17 schools, what kind of graph would you use? 12. What type of graph would you use to show seed growth of time?

13. Which two types of graphs might you consider if you wanted to represent different categories of information? 14. What type of graph plots different points and connects them with a line? 15. Which axis does the Y variable go on?

The following slides will show you answers. Please check them carefully. Remember-we are giving you answers so you can check your own work and go back and review things you missed. This is your test coming up Friday and all of these questions mirror questions from the test!

Please Check your answers… 1. Tuition and Fees 2. Board 3. Classical The higher the level of education, the lower the % unemployment inches

Please Check your answers… inches 8. Line Graph 9. X 10. Bar Graph 11. Circle Graph 12. Line Graph 13. Bar or Circle 14. Line Graph 15. Y