Answer: Yes, this means more rainfall causes apple trees to produce more fruit.
Explanation:
A positive correlation exists when one variable increases as the other variable increases.
Thus, a strong positive linear correlation between rainfall and the number of apples a tree produces definitely means that increase in rainfall will increase the a production of apple fruit.
Thus, a strong positive linear correlation between rainfall and the number of apples a tree produces means that more rainfall causes apple trees to produce more fruit.