Scatter Plots and Bivariate Data
What are Scatter Plots?
A scatter plot is a type of graph that shows the relationship between two different variables. Each point on the scatter plot represents one data pair, with one value determining the position on the x-axis and the other value determining the position on the y-axis.
Scatter plots help us visualize and analyze bivariate data — data that involves two variables measured for the same individuals or objects.
- Bivariate data: Data that involves two variables for the same set of individuals or objects
- Scatter plot: A graph showing the relationship between two variables
- Correlation: A measure of how strongly two variables are related to each other
Creating a Scatter Plot
To create a scatter plot:
- Identify your two variables (one for the x-axis, one for the y-axis)
- Draw and label your axes with appropriate scales
- Plot each data pair as a point on the graph
- Add a title and labels for both axes
Analyzing Scatter Plots
When analyzing a scatter plot, we look for patterns that tell us about the relationship between the variables:
Points trend from lower left to upper right. As one variable increases, the other tends to increase.
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Points trend from upper left to lower right. As one variable increases, the other tends to decrease.
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Points show no clear pattern. The variables don't appear to be related.
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