4. Thinking that someone is at the door when you hear the doorbell ring is an example of

Inference.

Explanation:

An inference is when a conclusion is made based on observation. This logical conclusion is made based on what has been and is observed.

When a conclusion can be arrived at based on the observation or previous observations, then this can be referred to as an inference. Thus, when one can know that someone is there at the door when the doorbell rings, then that is an example of inference.

Thus, the correct answer is inference.