FREE SAT Data Analysis & Statistics Questions and Answers 2

Question 1

A survey samples 200 students from a school of 2,000 to estimate the average hours of sleep per night. The sample mean is 6.8 hours. What does this tell us about the school population?

Accepted Answer

The school population is estimated to sleep an average of approximately 6.8 hours, with some uncertainty

Answer

Every student in the school sleeps exactly 6.8 hours per night

Answer

The survey is invalid because it did not survey all 2,000 students

Answer

No conclusions about the school can be drawn from a sample of only 200

Question 2

A data set has the following values: 5, 7, 7, 8, 9, 10, 100. Which measure of center would be MOST misleading as a description of 'typical' values?

Accepted Answer

Mean

Answer

Median

Answer

Mode

Answer

Range

Question 3

A graph shows that the number of library books checked out per month and the city's ice cream sales are both highest in summer. A researcher concludes that library visits cause ice cream purchases. This reasoning is flawed because:

Accepted Answer

Correlation does not imply causation — a third variable (summer season) likely drives both

Answer

Summer data is always unreliable for research purposes

Answer

The sample size of months is too small to draw conclusions

Answer

Ice cream and library books are too unrelated to be compared

Question 4

A box plot shows a distribution with the median significantly closer to the lower quartile than the upper quartile. This indicates the distribution is:

Accepted Answer

Right-skewed (positively skewed) — more values on the lower end with a tail extending higher

Answer

Approximately normal (symmetric)

Answer

Left-skewed (negatively skewed) — a tail extending toward lower values

Answer

Bimodal — having two peaks

Question 5

A researcher conducts an experiment where participants are RANDOMLY ASSIGNED to treatment and control groups. This design feature primarily controls for:

Accepted Answer

Confounding variables that might otherwise create spurious results

Answer

Measurement error in the data collection instruments

Answer

Sample size limitations affecting statistical power

Answer

Observer bias in data interpretation

Question 6

A student calculates that the correlation coefficient between study hours and test scores in their class is r = 0.85. What does this indicate?

Accepted Answer

There is a strong positive relationship between study hours and test scores, though this doesn't prove causation

Answer

Studying 0.85 more hours will increase test scores by 1 point

Answer

85% of students who study will pass the test

Answer

Test scores increase by 85% for each additional study hour