Section 3: Communicating with Graphs. Chapter 1 Section 3: Communicating with Graphs.

A Visual Display A graph is a visual display of information or data The horizontal axis or the X-axis is where you put the independent variable The vertical axis or the Y-axis is where the dependent variable goes.

Graphs are useful for displaying numerical information in business, science, sports, advertising, ect. There are many different types of graphs such as line, bar, and circle. Each type is used to display data in different ways, but you need to choose the appropriate format for the data.

Line Graphs Line graphs can show any relationship where the dependent variable changes due to the independent variable. Frequently shows changes over time You can show different variables on the same graph as long as relationship between the variables is the same. This can be very useful for comparing the outcome of similar products. Make sure the units are the same before putting them in the same graph.

Line Graph example Time Classroom Temp (˚C) A B C 16 5 17 16.5 10 19 15 20 21 17.5 23 18 25 18.5 Temperature In ˚C Time in minutes You can clearly see the relationship between the three variables being compared.

Bar Graphs This type of graph is useful for comparing information collected by counting. Each bar represents a quantity counted at a particular time, which should be stated on the graph.

Bar Graph Example Number of Students Number of Classrooms 20 1 21 3 22 23 2 24 25 5 26 27 Number of Classrooms Number of Students

Circle Graphs This type of graph is used to show how some fixed quantity is broken down into parts. The circular pie represents the total, while the slices represent percentages of the whole.

Circle Graph Example