melanoma and Latitude. Some studies have shown that, for certain ethnic groups, the incidence of melanoma (the most dangerous form of skin cancer) increases as latitude decreases.

In each case, state the correlation clearly.
(For example, we might state that “there is a positive correlation between variable A and variable B.”) Then state whether the correlation is most likely due to coincidence, a common underlying cause, or a direct cause. Explain your answer.