We have to find the relation between these two variables:
• Ice cream cones sold
,
• Number of people wearing sunglasses
We can think that more people wearing sunglasses indicate a sunny weather: the sunnier the day, the more likely is for people to wear sunglasses.
Sunny weather will also have an effect on the number of ice cream sold, as it is usally a higher temperature. Then, the sunnier the day, the more ice cream are expected to be sold.
We then can expect a positive correlation between the two variables.
This does not necessarily mean that the relation is causal. In this case, there is a third variable that is not present (the sunny weather) that is the cause of the positive correlation.
Then, there is a positive correlation but not a causal relationship as there us a third variable (hot weather) that is the cause of the correlation.
Answer: Positive correlation but not causal relationship {Third option].