LEAP Interpreting Scientific Data 2 — Questions and Answers
Question 1: A bar graph shows plant heights after 4 weeks: Group A (no fertilizer) averaged 12 cm, Group B (fertilizer) averaged 19 cm. What does this data best support?
- Fertilizer has no effect on plant growth
- Fertilizer increases plant height (Correct answer)
- Group A plants are healthier than Group B plants
- Both groups grew at the same rate
Correct answer: Fertilizer increases plant height
Group B plants grew taller on average, indicating fertilizer had a positive effect on plant height.
Question 2: A scientist records water temperature in a lake every hour. The data shows temperature rises from 6 AM to 2 PM, then falls until midnight. What type of variable is time in this experiment?
- Dependent variable
- Controlled variable
- Independent variable (Correct answer)
- Extraneous variable
Correct answer: Independent variable
Time is the independent variable because it is deliberately tracked and does not depend on water temperature.
Question 3: Two students measure the length of the same pencil. Student A records 14.2 cm and Student B records 14.8 cm. What is the most likely source of this difference?
- The pencil changed length between measurements
- Measurement error or different reading techniques (Correct answer)
- Different units were used
- The rulers had different numbers of centimeters
Correct answer: Measurement error or different reading techniques
Small differences between measurements of the same object typically result from human measurement error or technique variation.
Question 4: A line graph shows CO₂ levels in the atmosphere from 1960 to 2020. The line slopes consistently upward. What conclusion is best supported?
- CO₂ levels fluctuate randomly over time
- CO₂ levels have steadily increased over 60 years (Correct answer)
- CO₂ levels peaked in 1990 and then declined
- There is no trend in CO₂ data
Correct answer: CO₂ levels have steadily increased over 60 years
A consistently upward-sloping line indicates a steady increase in CO₂ levels over the measured time period.
Question 5: In a table of experimental results, which row shows an outlier if the other rows all show reaction times between 0.20 and 0.25 seconds?
- Trial 3: 0.22 seconds
- Trial 5: 0.24 seconds
- Trial 7: 0.19 seconds
- Trial 9: 0.87 seconds (Correct answer)
Correct answer: Trial 9: 0.87 seconds
An outlier is a data point far outside the range of the other values; 0.87 seconds is far above the 0.20–0.25 range.
Question 6: A pie chart shows that 45% of a school's waste is paper, 30% is food, 15% is plastic, and 10% is other. Which waste type makes up the largest share?
- Food
- Plastic
- Paper (Correct answer)
- Other
Correct answer: Paper
Paper represents 45% of the waste, which is the largest portion shown in the pie chart.
Question 7: A scientist graphs the relationship between sunlight hours and crop yield. The data points form a positive correlation. What does this mean?
- As sunlight hours increase, crop yield decreases
- As sunlight hours increase, crop yield also increases (Correct answer)
- Sunlight hours have no relationship to crop yield
- Crop yield causes changes in sunlight hours
Correct answer: As sunlight hours increase, crop yield also increases
A positive correlation means both variables increase together — more sunlight corresponds to higher crop yield.
LEAP Interpreting Scientific Data 2
A bar graph shows plant heights after 4 weeks: Group A (no fertilizer) averaged 12 cm, Group B (fertilizer) averaged 19 cm.
What does this data best support?