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An outlier in a regression analysis shows up in a residuals plot as a point that is:
AAt the origin only
BPerfectly average
CFar from the rest
DExactly on the axis
Answer & Solution
Correct answer: C. Far from the rest
1. A correctly fitted model leaves residuals that scatter evenly around zero.
2. A residuals plot should appear random, with no pattern and no outliers.
3. A point sitting far away from that even scatter is therefore flagged as an outlier.
4. Outliers can pull the fitted line noticeably, which is why they are checked for.
5. Being at the origin or at the average is exactly what an outlier is not.
_Source: OpenStax Introductory Statistics 2e (CC BY 4.0), Ch 12 'Linear Regression and Correlation', sections 12.1-12.6_
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