Sarah observed that different kinds and amounts of fossils were present in a cliff behind her house. She wondered if changes in fossil content occurred from the top to the bottom of the cliff. She marked the cliff at five positions: 5, 10, 15, 20 and 25 meters from the top. She dug out and removed 1 bucket of soil from each of the positions and determined the kind and
number of fossils in each sample.
What was the hypothesis?