Final answer:
Forming a hypothesis is the step in the problem-solving process where a proposed explanation is created after an observation is made and a question is asked.
Step-by-step explanation:
The step of the problem-solving process that involves creating a proposed explanation is known as forming a hypothesis. This is typically Step 2 in the scientific method, which follows after making an observation and asking a question. A hypothesis is a tentative explanation for the observations made.
It is not merely any guess; it must be based on scientific knowledge, logical, and falsifiable. For instance, seeing the pattern of light and darkness correlating with the movement of celestial bodies can lead to forming hypotheses about the nature of Earth's rotation and orbit.