AP Statistics FRQ practice

Write AP Statistics free-response answers in an exam-style editor, or browse the questions by type: Question 2 FRQ and Question 4 FRQ.

📊AP Statistics

Each FRQ type tests specific skills taught in particular units. Here's why certain units appear for each question type:

FRQ	Focus	Units	Why
FRQ 1	Multi-Focus on Practices 1 and 2	1	Tests formulating an investigative question and collecting data (sampling, experimental design)
FRQ 2	Multi-Focus on Practices 3 and 4	1, 2, 5	Tests analyzing data and interpreting results — graphs, summary statistics, probability, regression output
FRQ 3	Inference	3, 4	One complete inference procedure — a hypothesis test or confidence interval for proportions or means
FRQ 4	Multi-Focus on Practices 2, 3, and 4	All	Combines content areas across the course, assessing collecting, analyzing, and interpreting together

This mapping reflects College Board's exam structure - each FRQ type tests specific skills that are taught in particular units.

Practice FRQ 1 of 81/8

1. A regional airport authority is investigating passenger wait times at security checkpoints to improve operational efficiency.

The airport authority initially proposes the following investigative question: "Do passengers wait a long time at security?"

Identify one flaw in this investigative question and state a refined investigative question that addresses the flaw, specifies the population, and focuses on a quantitative variable.

To collect data, an airport official suggests recording the wait times of the first 100 passengers who enter the security line on a Tuesday at 5:00 AM.

Identify the sampling method proposed. Explain how this method could introduce bias into the estimate of the mean security wait time for all passengers at this airport, and state the likely direction of the bias.

The authority decides instead to use a stratified random sample of 300 passengers, using the time of day (morning, afternoon, evening) as the strata.

Describe a procedure the airport authority could use to select this stratified random sample.

In a separate study, the airport authority wants to determine if a new automated bin-return system reduces passenger wait times compared to the standard system. They recruit 150 volunteer passengers and randomly assign 75 to use the new automated system and 75 to use the standard system.

Explain why this study design allows the authority to establish a cause-and-effect relationship, and identify the population to which the results of this study can be appropriately generalized.