Wednesday, October 29, 2008

Scatterplot


Scatter plots are similar to line graphs in that they use horizontal and vertical axes to plot data points. Scatter plots have a very specific purpose in that they show how much one variable is affected by another. The relationship between two variables is called their correlation .


Scatter plots usually consist of a large body of data. The closer the data points to making a straight line when plotted, the higher the correlation between the two variables and the stronger their relationship. Scatterplots should be constructed when the relationship between two variables is of interest.
The above scatterplot is interesting, as it plots the age of husbands versus the age of their wives. It shows that ages among husband and wife have a high correlation (people tend to marry others around their same age).



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