Correlation and linear regression

Read correlation with the scatter · Diagrams

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Outlier in a rising scatter

Inspect how an outlier changes the pattern

Compare the patterns below.

Source outlier in a rising pattern

14 points

The other points lie closer to a rising straight-line pattern.

Ringed point: Source outlier (2, 7).

The source identifies (2, 7) exactly. Other point positions in this reconstruction are schematic; no complete numerical data set is supplied.
In this example, the source states that removing (2, 7) raises the positive correlation because the remaining pattern is closer to a rising straight line.
An outlier can increase or decrease a correlation coefficient. Investigate the observation and context before deciding whether exclusion is justified.

Fourteen-point source scatter reconstructed schematically, with the explicitly stated outlier (2,7) above the otherwise rising pattern. Removing it raises the positive correlation in this source example. Remaining coordinates are not supplied as a numerical dataset.

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