A thermometer shows that the air temperature is 56°F. A mineral sample of galena produced a gray-black streak when tested. Based on previous data, ten hurricanes may occur in the year 2013. A weather vane indicates the wind is coming from the west.
I gave my students this multiple choice question: Which statement is an inference?

Only one answer is correct among these 4 choices:
- A thermometer shows that the air temperature is 56°F.
- A mineral sample of galena produced a gray-black streak when tested.
- Based on previous data, ten hurricanes may occur in the year 2013.
- A weather vane indicates the wind is coming from the west.

Could you tell me which one is correct?

Based on previous data, ten hurricanes may occur in the year 2013.