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(Chapter 8, STAT 1040)
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# Correlation
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## Scatter Diagrams
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A scatter diagram or scatter plot shows the relationship between two variables. One variable is on the X axis, the other on the Y axis.
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### Association
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- Positive association is demonstrated when the dots are trend upward as `x` increases.
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- Negative association is demonstrated when the the dots trend downward as `x` increases.
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- Strong association is demonstrated when dots are clustered tightly together along a line.
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- Weak association is demonstrated when dots are not clustered tightly.
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## Correlation
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Correlation is between `-1` and `1`. Correlation near 1 means tight clustering, and correlation near 0 means loose clustering.
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# Terminology
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| Term | Definition |
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| `r` | Correlation Coefficient |
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