Experiment Design Analysis - Fossils in Cliff

Jose observed that different kinds and amounts of fossils were present in a cliff behind his house. He wondered what changes in fossils content occurred from the top to the bottom of the bank. He marked the bank at five positions: 5, 10, 15, 20 and 25 meters from the top. He removed one bucket of soil from each position and determined the kind and number of fossils in each sample.

  1. Make a sketch of the fossils in the cliff:
     
     
     
     
     
     
     
     
     
  2. Question/Problem:
     
     
     
  3. Hypothesis with a prediction:
     
     
     
  4. Manipulated variable:
     
     
  5. Levels of treatments:
     
     
  6. Responding variable:
     
     
  7. Controlled variable:
     
     
  8. How would you improve this experiment?