ISAT - International Student Admissions Interpreting Scientific Data Questions and Answers

Question 1

A researcher is testing the effectiveness of a new drug on reducing high blood pressure. One group of participants receives the new drug, while a second group receives a pill that looks identical but contains no active ingredient. What is the primary purpose of the second group?

Accepted Answer

To act as a control group, providing a baseline to measure the drug's true effect against.

Answer

The second group, known as a placebo or control group, is crucial in a clinical trial. By comparing the results of the group taking the active drug to the group taking the placebo, researchers can isolate the drug's specific effects from other factors, such as the placebo effect (where patients improve simply because they believe they are receiving treatment) or natural variations in blood pressure.

Question 2

A study finds a strong positive correlation between the number of hours students spend in the library per week and their final exam scores. The authors conclude that spending more time in the library causes higher exam scores. Why might this conclusion be flawed?

Accepted Answer

Correlation does not imply causation; another factor, such as a student's level of motivation, could influence both library time and exam scores.

Answer

This is a classic example of confusing correlation with causation. While the two variables are related, it's possible a third, unmeasured variable (a confounding variable) is the true cause. For example, highly motivated students are more likely to both spend time in the library and study effectively elsewhere, leading to higher scores. The library time itself might not be the direct cause.

Question 3

The table below shows the results of a clinical trial for a new allergy medication. The data indicates the percentage of patients in different age groups who reported 'significant symptom relief'.

| Age Group | Placebo Group Relief | Medication Group Relief |
|---|---|---|
| 18-35 | 25% | 60% |
| 36-55 | 30% | 55% |
| 56+ | 28% | 45% |

Which statement is the most accurate interpretation of the data?

Accepted Answer

The medication provided the greatest benefit, compared to the placebo, for the 18-35 age group.

Answer

To find the medication's benefit, subtract the placebo relief rate from the medication relief rate for each group. For 18-35, the benefit is 60% - 25% = 35%. For 36-55, it's 55% - 30% = 25%. For 56+, it's 45% - 28% = 17%. The largest difference (35%) is in the 18-35 age group, indicating the greatest relative benefit for them.

Question 4

The provided graph shows the population of a certain species of fish in a lake over 10 years, during which a new industrial plant began operations in year 5. The graph shows a steady population from year 1 to 5, followed by a sharp decline from year 6 to 10. Which of the following statements is a valid conclusion based *only* on the data presented?

Accepted Answer

The fish population began to decrease after the industrial plant started operations.

Answer

The data shows a temporal relationship: the plant began operations, and then the population declined. This is an observation of correlation in time. However, the graph alone does not provide evidence to prove causation (A), predict the future with certainty (D), or make broad claims about the entire ecosystem's recovery (C). Stating only what the graph shows—that the decrease occurred after the plant opened—is the only fully supported conclusion.

Question 5

A scientist measures the boiling point of pure water at various altitudes. The results are shown in the table below.

| Altitude (meters) | Boiling Point (°C) |
|---|---|
| 0 | 100.0 |
| 1000 | 96.7 |
| 2000 | 93.4 |
| 4000 | 86.8 |

Based on the trend in the data, what is the MOST LIKELY boiling point of water at an altitude of 3,000 meters?

Accepted Answer

90.1°C

Answer

The data shows that the boiling point decreases as altitude increases. The 3,000-meter altitude is exactly halfway between 2,000 meters (93.4°C) and 4,000 meters (86.8°C). To estimate the boiling point at this intermediate altitude (a process called interpolation), one can find the midpoint of the temperatures. The average of 93.4 and 86.8 is (93.4 + 86.8) / 2 = 90.1°C. This is the most logical estimate based on the linear trend between these two points.

ISAT - International Student Admissions Test Practice Test

ISAT - International Student Admissions Test Practice Test

ISAT - International Student Admissions Interpreting Scientific Data Questions and Answers