AZSCI Analyzing & Interpreting Data 2

Question 1

A student team measures the boiling point of a saline solution five times, recording the following temperatures: 102.5°C, 102.7°C, 102.6°C, 108.3°C, and 102.4°C.
The value 108.3°C is a significant outlier.
What is the most scientifically rigorous next step for the team to take?

Accepted Answer

Repeat the entire experiment, focusing on controlling variables that might have caused the anomalous reading.

Answer

Discard the outlier and calculate the average of the remaining four values.

Answer

Average all five values, including the outlier, to represent all collected data.

Answer

Report the median of the five values instead of the mean, as it is less affected by outliers.

Question 2

Two different scientific models are proposed to predict the annual migration pattern of a bird species. Model A is simpler and based on temperature changes. Model B is more complex, incorporating temperature, daylight hours, and food source availability. When tested against 10 years of historical data, Model B is slightly more accurate. However, a new study provides 5 years of data from a period of unusual climate activity. In this new dataset, Model A's predictions are significantly more accurate than Model B's. What is the best interpretation of this outcome?

Accepted Answer

Model B may be 'overfit' to the original dataset, making it less effective at predicting outcomes under novel conditions.

Answer

Model B is flawed and should be discarded in favor of the simpler Model A.

Answer

Model A is fundamentally better because it is more robust to unusual conditions.

Answer

The new dataset must be erroneous because it contradicts the initial finding that Model B was more accurate.

Question 3

A researcher analyzes two datasets about a local ecosystem. Dataset 1 is a line graph showing a steady increase in the population of an invasive insect species over five years. Dataset 2 is a data table showing the average population of three native bird species over the same five years. To synthesize this information into a valid scientific claim, what must the researcher do?

Accepted Answer

Look for a correlation between the trends and propose a testable hypothesis about the relationship, acknowledging it is not proof of causation.

Answer

Assume a direct causal link and state that the invasive insect is harming all native bird populations.

Answer

Create a single graph that plots all the data together to see if the lines overlap.

Answer

Summarize the findings of each dataset separately without attempting to link them.

Question 4

A student measures the mass of a rock as 15.3 grams. The digital scale has a known uncertainty of ±0.2 grams. Which of the following statements most accurately and completely represents this measurement and its uncertainty?

Accepted Answer

The measurement has a relative uncertainty of approximately 1.3%.

Answer

The rock's mass is exactly 15.3 grams.

Answer

The rock's mass is somewhere between 15.1 and 15.5 grams.

Answer

The measurement is precise but not necessarily accurate.

Question 5

After observing that a specific brand of fertilizer appears to increase tomato plant yield, a student concludes, 'Fertilizer X causes an increase in tomato production.' Based on this observational data alone, what is the most significant logical limitation of this conclusion?

Accepted Answer

The conclusion confuses correlation with causation, as other variables were not controlled.

Answer

The student did not measure the exact weight of the tomatoes produced.

Answer

The observation was only made on one type of plant (tomatoes).

Answer

The student did not use a large enough sample size of tomato plants.

Question 6

A scientist presents a scatter plot with a line of best fit. Many of the data points lie far from the line. Which of the following is the most appropriate interpretation of this data representation?

Accepted Answer

A linear model may not be the best fit for this data, or there is a high degree of variability in the relationship.

Answer

The data is of poor quality and the entire experiment should be invalidated.

Answer

The line of best fit is incorrect and should be redrawn to pass through more points.

Answer

The outliers should be removed until the remaining points form a clear linear pattern.