AP Stats Sampling Methods and Design

Question 1

What is the purpose of random sampling?

Accepted Answer

To ensure every member of the population has an equal chance of being selected

Answer

Random sampling gives each population member an equal selection probability, reducing selection bias and supporting generalizability.

Question 2

What is stratified sampling?

Accepted Answer

Dividing the population into subgroups and sampling from each proportionally

Answer

Stratified sampling ensures representation of important subgroups by dividing the population into strata and sampling from each.

Question 3

What is sampling bias?

Accepted Answer

A systematic error that results in a non-representative sample

Answer

Sampling bias occurs when the selection method systematically favors certain members over others, producing unrepresentative results.

Question 4

What determines the minimum sample size needed for a study?

Accepted Answer

Desired confidence level, margin of error, and population variability

Answer

Sample size calculations consider the desired precision, confidence level, population variability, and effect size.

Question 5

What is cluster sampling?

Accepted Answer

Dividing the population into clusters, then randomly selecting entire clusters to study

Answer

Cluster sampling randomly selects groups (clusters) rather than individuals, then studies all members within selected clusters.

AP Practice Test