A gardener measured the amount of fertilizer applied to 11 plants and the plants’ heights after 4 weeks. The scatterplot shows fertilizer (grams) on the x-axis and height (cm) on the y-axis, with a solid line of best fit. Which statement best describes the relationship shown?
- There is a strong negative association: more fertilizer generally means shorter plants.
- There is little to no association: plant height does not change with fertilizer amount.
- There is a moderate positive association: more fertilizer generally means taller plants. (correct answer)
- Fertilizer causes taller plants for every individual plant in the study.
Explanation: This question asks us to describe the relationship between fertilizer amount and plant height. Examining the scatterplot, as fertilizer increases (moving right on x-axis), plant height generally increases (moving up on y-axis), and the solid line of best fit has a positive slope. This indicates a moderate positive association - the relationship exists but points show some scatter around the line. The key error to avoid is confusing association with causation; option D incorrectly claims causation for every individual plant. Remember that scatterplots show associations, not proof of cause-and-effect relationships.