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Click on the Graphing worksheet set you wish to view below.
How are data tables and graphs used in the real world?
Data tables are used to collect information, and graphs are used to present the same information. Usually, we see graphs in their final form - in newspapers, on TV, or on the Internet. The data tables have the details, but aren't normally published.
In scientific research, data tables are quite often mined for additional information. In our example, we only show the averages and we do not mention whether the student was a boy or a girl. We could find that information by going back to the data table.
A basic problem graphing.
Because a graph is a picture, it should be balanced and attractive. One problem in constructing a graph is deciding the range. In the graph above, the scale on the left goes from zero to twenty and has lines across at every 10 hours. Would the graph be better if there were lines at 5, 10, 15 and 20?
The range across the bottom goes from A to E. But no one got an E in the class - should that be left out?
Finally, the colors might be changed to make the graph easier to read - or there could be black borders put around the bars. All these decisions go into making an attractive and meaningful graph.
What are data tables?
A data table is just a way to organize information. It's a sheet you fill out that has columns and rows so you can enter data in a standard way. Here is an example:
The table records the number of hours of TV each student watches and puts it in the column that matches their current grade in math class. At the bottom, the number of hours for that column is averaged (and rounded to the nearest half-hour).
What is Graphing?
Graphing is a way to present data from a data table. Because a data table by itself can be confusing, the information in it is put in a labeled picture form. This makes it easier to understand - but it is the same data, just in a different form.
Here is a graph for the data table in the example above:
From the graph, it is easier to see that more hours of TV is linked to a lower grade (on average) for the students in this class.
An interesting fact about graphing.
Sometimes, graphs can be misleading. They can have accurate information, but present a different picture. Let us say that you run a TV station and want to show that TV doesn't affect grades much at all. In a sense, you want to fool people.
Here is the same graph as above with one slight change: the scale on the left is increased so much that all the bars appear to be almost the same height. Notice how the impression is much different than our first graph with the same information.