Statistics › Section L · Linear regression and correlation › Topic L.2
Scatterplots and the correlation coefficient
Does studying raise scores? Does price track quality? Two quantitative variables meet in a scatterplot, and the correlation coefficient r compresses their relationship into one number - direction, strength, and one strict limit: straightness only.
In this topic
- Two variables meet
- The correlation coefficient r
- Reading r's magnitude
- r is unitless and scale-proof
- Worked example: computing r by hand
- Worked example: scale-proof in action
- Outliers and influential points
- Correlation is not causation
- Simpson's paradox: aggregation can flip a pattern
- Common mistakes to avoid
- Key takeaways
This topic is part of Wuanberri Pro. Checking your access…