Answer:
3. positive correlation but not causal relationship
Explanation:
A positive correlation is when one factor increases, the other factor increases as well.
A negative correlation is when one factor increases, the other factor decreases.
A causal relationship is when one factor causes the other factor change in a certain way (i.e. increase or decrease).
More people buy ice cream as the day becomes hotter and sunnier. This also applies to people choosing to wear sunglasses. Therefore, there is a positive correlation between the two (because both increase). However, this is not a causal relationship because the cause of both is the hotter and sunnier day.
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