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

A representative sample allows inference about the population — the sample mean (6.8 hours) is an estimate of the population mean, with a margin of error depending on sample size and variability.

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

The mean is pulled upward by the extreme outlier (100) to approximately 20.9, while most values cluster between 5 and 10. The median (8) better represents the 'typical' value. The mean is most misleading here.

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

Both library visits and ice cream sales increase in summer — but summer (a third variable, or 'confound') is the underlying cause of both. This is classic spurious correlation driven by a confounding variable.

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

When the median is closer to the lower quartile (Q1) and the upper 'box' extends further, the distribution has more scores in the lower range and a longer tail extending toward higher values — this is right (positive) skew.

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

Random assignment distributes both known and unknown confounding variables equally between groups — making the groups comparable so that any observed difference can be attributed to the treatment.

Bluebook SAT Practice Test Practice Test

Bluebook SAT Practice Test Practice Test

FREE SAT Data Analysis & Statistics Questions and Answers 2