Practice question · Multiple choice
Ice cream sales correlate with drowning deaths at r = 0.9. What is the most useful thing that correlation tells you?
Hints
- Ask what both variables have in common that neither causes.
- The correlation is real and the causal reading is wrong. What is the correlation good for?
Show the answer
C. That something makes both move together, here summer heat
Why
The correlation is genuine and points at a shared cause rather than a link between the two. Option 3 overcorrects into uselessness: correlation is how confounders get noticed in the first place, and 'find the third variable' is a productive instruction, it is only the automatic causal reading that fails.
Practise Hypothesis Testing
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