ATAR Scientific Inquiry & Understanding 3 — Questions and Answers
Question 1: A line of best fit on a scatter plot is drawn to:
- Connect all data points in order
- Show the general trend while minimizing the distance from all data points (Correct answer)
- Pass through the origin always
- Highlight the outliers in the dataset
Correct answer: Show the general trend while minimizing the distance from all data points
A line of best fit represents the overall trend of the data and minimizes residual distances from individual points.
Question 2: An outlier in a dataset should be:
- Always removed to improve the average
- Automatically included in all calculations without question
- Investigated to determine whether it results from error or a genuine observation (Correct answer)
- Reported only if it supports the hypothesis
Correct answer: Investigated to determine whether it results from error or a genuine observation
Outliers may indicate experimental error or a significant finding, so they must be investigated rather than automatically discarded.
Question 3: Which of the following is an example of qualitative data?
- The mass of a sample in grams
- The temperature at which a reaction occurs
- The color change observed during a chemical reaction (Correct answer)
- The volume of gas produced per minute
Correct answer: The color change observed during a chemical reaction
Qualitative data describes non-numerical characteristics such as color, texture, or appearance.
Question 4: A placebo is used in medical trials to:
- Replace the experimental drug with a cheaper alternative
- Ensure participants are aware of which treatment they receive
- Control for the psychological effect of receiving treatment (Correct answer)
- Increase the dosage given to the control group
Correct answer: Control for the psychological effect of receiving treatment
Placebos control for the placebo effect, ensuring observed results are due to the treatment rather than participant expectations.
Question 5: When a scientist states a result is 'statistically significant,' it means:
- The result is large enough to be practically important
- The result is unlikely to have occurred by chance alone (Correct answer)
- The experiment was repeated more than ten times
- The hypothesis has been proven beyond doubt
Correct answer: The result is unlikely to have occurred by chance alone
Statistical significance indicates that the probability of the result occurring by random chance is below an accepted threshold (commonly p < 0.05).
Question 6: A double-blind study is designed so that:
- Both the researchers and participants are unaware of who receives the treatment (Correct answer)
- Only participants are unaware of the hypothesis
- Researchers observe results without using instruments
- Data is collected from two independent research groups
Correct answer: Both the researchers and participants are unaware of who receives the treatment
In a double-blind study, neither the participants nor the researchers assessing outcomes know the group assignments, reducing bias.
Question 7: Which type of graph is most appropriate for displaying the proportion of different categories in a whole dataset?
- Line graph
- Scatter plot
- Pie chart (Correct answer)
- Histogram
Correct answer: Pie chart
Pie charts display parts of a whole and are ideal for showing percentage or proportional breakdowns of categorical data.
ATAR Scientific Inquiry & Understanding 3
A line of best fit on a scatter plot is drawn to: