Graphing in Science
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Parts of a Graph
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(y-axisdependent variable)
(x-axisindependent variable)
Line Graphs• Line graphs compare two variables (one is
often time).
• For displaying data or information that changes continuously over time.
• They enable the viewer to make predictions about the results of data not yet recorded .
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Line Graph Set-Up
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Pie Graphs• Pie graphs (sometimes called circle charts)
are used to show the parts that make up a whole.
• They can be useful for comparing the size of relative parts.
• Usually used for percentages (%).
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Pie Graph
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Bar Graphs• Make comparisons between
different groups (variables). • The bars do not touch.
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Bar Graph
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Bar Graphs Set-Up
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Histograms• Use histograms when y-axis gives the rate
of, or occurrences for continuous data that has been sorted into groups, for example, 20-24 meters.
• All bars are usually of equal width.
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Histograms
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Histogram Set-Up
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Scatter Plot Graphs• Scatter plots has points that show
relationship between two sets of data (e.g., students’ study time and their grades).
• Scatter plots usually consist of a large body of data. The closer the data points come when plotted to making a straight line, the higher the correlation (relationship) between the two variables, or the stronger the relationship.
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Scatter Plot Graph
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Scatter Plot GraphsIf there is absolutely no correlation present then R2 =
0
The closer R2 is to 1 or -1, the stronger the correlation, or the stronger the relationship between the variables
The closer R2 is to 0, the weaker the correlation
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Scatter plot graphs• A perfect positive
correlation is given the value of 1
• A perfect negative correlation is given the value of –1
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