Plant growth comparison under different sunlight durations over 11 days.

The image presents a line graph showing the growth of tomato plants over time, measured in days, under different amounts of sunlight: 1 hour, 3 hours, 6 hours, and 9 hours per day. The vertical axis represents plant height in millimeters (mm), and the horizontal axis represents the day on which the plant was measured (from Day 4 to Day 11).

Let’s analyze the data and solve the problem step by step.

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Step 1: Understand the Graph

- X-axis (Horizontal): Days (4 to 11)
- Y-axis (Vertical): Height in mm (0 to 180 mm)
- Lines:
- Dotted line with diamonds (♦): 1 hour of sunlight
- Solid line with triangles (▲): 3 hours of sunlight
- Dashed line with squares (■): 6 hours of sunlight
- Dash-dot line with crosses (×): 9 hours of sunlight

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Step 2: Interpret Growth Trends

We observe:

1. 1 Hour of Sunlight (♦):
- Very slow growth.
- Starts at ~10 mm on Day 4 and barely increases.
- Ends around 15–20 mm on Day 11.
- Conclusion: Minimal growth due to insufficient light.

2. 3 Hours of Sunlight (▲):
- Moderate growth.
- Starts at ~20 mm and increases to about 90 mm by Day 11.
- Shows steady increase with some fluctuations.
- Conclusion: Better than 1 hour but still limited.

3. 6 Hours of Sunlight (■):
- Stronger growth.
- Starts at ~25 mm and reaches ~45 mm by Day 11.
- Growth is consistent but not as high as 9 hours.
- Conclusion: Good growth, but not optimal.

4. 9 Hours of Sunlight (×):
- Most rapid and highest growth.
- Starts at ~40 mm and climbs to nearly 160 mm by Day 11.
- Steady upward trend with minor dips.
- Conclusion: Optimal sunlight for maximum growth.

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Step 3: Answer Likely Questions (Inferred from Graph)

Since no specific question was stated, here are possible interpretations or questions that could be asked:

#### Q1: Which amount of sunlight results in the greatest plant growth?
✔ Answer: 9 hours of sunlight results in the greatest growth. Plants receiving 9 hours grow from ~40 mm to ~160 mm, significantly more than others.

#### Q2: How does increasing sunlight affect plant growth?
✔ Answer: Increasing sunlight generally increases plant growth. There's a clear positive correlation between sunlight duration and plant height, with the best results at 9 hours.

#### Q3: What happens to plant growth when sunlight is less than 6 hours?
✔ Answer: Growth is significantly reduced. With only 1 or 3 hours, plants grow very slowly, indicating sunlight is a limiting factor.

#### Q4: On which day did the 9-hour group reach 140 mm?
✔ Answer: Looking at the graph:
- At Day 8: ~140 mm
- So, Day 8 is when the 9-hour group reached approximately 140 mm.

#### Q5: Compare growth rates between Day 4 and Day 11 for all groups.
✔ Answer:
| Sunlight | Height (Day 4) | Height (Day 11) | Growth |
|---------|----------------|------------------|--------|
| 1 hr | ~10 mm | ~20 mm | +10 mm |
| 3 hr | ~20 mm | ~90 mm | +70 mm |
| 6 hr | ~25 mm | ~45 mm | +20 mm |
| 9 hr | ~40 mm | ~160 mm | +120 mm |

→ The 9-hour group has the highest growth rate.

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Final Conclusion:

Plants grow best with 9 hours of sunlight per day, as shown by the highest final height and steepest growth curve. Sunlight is a key factor in plant development—more sunlight leads to greater photosynthesis, resulting in faster and taller growth.

> 🌱 Key Takeaway: For optimal tomato plant growth, provide at least 6–9 hours of sunlight daily, with 9 hours being ideal based on this experiment.

Let me know if you'd like to calculate average growth rate or predict future height!