Final answer:
A statement that explains observations and can be tested is called a hypothesis. It's a starting point in the scientific process, providing a testable prediction, and it can lead to the development of a theory if supported by significant evidence.
Step-by-step explanation:
A statement that explains observations and can be tested is called a hypothesis. A hypothesis is defined as a tentative explanation for an observation, or, more precisely, for a series of observations. It represents an educated guess that forms the base for further investigation through controlled experimentation. Once a hypothesis is tested repeatedly and supported by evidence, it may contribute to the formulation of a scientific theory. It's important to understand that while all these elements—hypotheses, theories, and laws—interrelate, they serve different roles within the scientific method.
In summary, a hypothesis is a starting point in the scientific process, offering a testable prediction. A theory, on the other hand, is a well-substantiated explanation of some aspect of the natural world that is supported by a significant body of evidence and is consistent with pre-existing experimental results and predictions. Lastly, a scientific law is a statement that summarizes the predictable relationships between variables, often mathematically.