Correlation detective
Uncover a hidden line by removing planted anomalies from a scatterplot.
Find one unusual point
1 question · No time limit
Example
Example
Remove one point to make the remaining linear relationship as strong as possible.
Planted anomalies in this constructed puzzle: 1. Strength means the absolute value of Pearson’s correlation r, so a downward line can be just as strong as an upward line.
1. Predict
Make a prediction first. It is not scored.
2. Test your idea
- Removed
- 0 / 1
- Correlation
- 0.768
Points to remove before checking: 1.
Data values
Try the controls, then check your solution.
Why?
Remove D. The correlation changes from 0.768 to 0.999; its absolute value becomes 0.999.
Among all permitted removals, this leaves the strongest linear relationship.
Correlation describes association. This pattern alone does not show that one variable causes the other.
Revisit your prediction
Cleaned pattern: Upward. Its correlation is 0.999; the sign tells you the direction.
Keep exploring the experiment.
3. Change the rules
A linked challenge. This answer is not scored.
Continue your unfinished round
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Continuing uses no additional practice start.
Discard the unfinished round?
Your answers from this round will be discarded. You can choose your settings before starting a new round.
Starting the new round uses one practice start.
- Answered
- 0 / 1
- Active time
- 0:00
Round complete.
Optional and off by default. Share starts, completions, replays and error categories. For visits from ChatGPT, starts and completions can also include the first QuickenBrain page and broad country. No answers, drawings or names.
How this data is usedHelp
Try the controls, then check your solution.
Your first checked solution is recorded. You can keep experimenting afterwards.
About this practice
Learn a method
Inspect the scatterUncover a hidden line by removing planted anomalies from a scatterplot.
For a broader mix of practices, explore the statistics practice test. Membership is required to start a test.
Report a problem
Optional and off by default. Share starts, completions, replays and error categories. For visits from ChatGPT, starts and completions can also include the first QuickenBrain page and broad country. No answers, drawings or names.
How this data is used