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