Graphs
In your textbook this is from section 1.4 in your textbook
Data Tables
• Scientists organize their data by using tables and graphs
• A data table is a very easy way to present and organize data
• On p. 22 in your textbook is an example of a data table
• This table has location and average annual precipitation for several cities
Data Tables
• On this particular table the location is the manipulated variable (what we know as the independent variable)
• The average annual precipitation is the responding variable (what we know as the dependent variable)
Line Graphs
• A line graph can be used to show changes that happen when the two variable are related
• The independent variable is graphed along the x-axis (the horizontal axis)
• The dependent variable is graphed along the y-axis (the vertical axis)
http://erc.msh.org/quality/foutools/foulngrf.cfm
Line Graph
Slope• When looking at a line graph it is important to
notice the slope which is the ratio of the vertical change to the corresponding horizontal change
• Slope = rise/run• Rise is the change in the y variable• Run is the corresponding change in the x variable• p. 23 in your text has an example of mass vs.
volume of water
Direct and Inverse Proportion
• Direct proportion is when the ratio of the two variables is constant
• This can be seen in the mass vs. volume of water graph
• Inverse proportion is when the product of the two variables is a constant
• This can be seen in the Time to fill a 1-gallon pot with water graph
Bar Graphs
• A bar graph is used to compare a set of measurements, amounts or changes
• P. 24 in your text has an example of the Average Annual Precipitation for Selected U.S. Cities
• Notice how it is easy to see the precipitation differences between each city
Bar Graph
Circle Graphs
• A circle graph shows how a part or share of something relates to the whole
• An example of a circle graph can be seen on p. 24 in your textbook
• This circle graph shows the Composition of the Earth’s crust (shows the percent of elements in the Earth’s crust)
Circle Graph (also known as pie graph)
Presenting Data
• Scientists need to present the results of their experiments in scientific journals or magazines
• Data can be interpreted in different ways• Advertisers often use tables and charts to
make their product look better to us• Data needs to be presented clearly and
honestly