Fiveable
📊AP Statistics
​

📊AP Statistics

FRQ 1 – Multi-Focus on Practices 1 and 2
​
Unit 1: Exploring One-Variable Data and Collecting Data
​
AP Stats FRQ Types & Units

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

FRQFocusUnitsWhy
FRQ 1Multi-Focus on Practices 1 and 21Tests formulating an investigative question and collecting data (sampling, experimental design)
FRQ 2Multi-Focus on Practices 3 and 41, 2, 5Tests analyzing data and interpreting results — graphs, summary statistics, probability, regression output
FRQ 3Inference3, 4One complete inference procedure — a hypothesis test or confidence interval for proportions or means
FRQ 4Multi-Focus on Practices 2, 3, and 4AllCombines 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 111/11

1. An aerospace engineering firm produces a new batch of 10,000 titanium bolts used in aircraft assembly. The quality control department wants to investigate the tensile strength, measured in megapascals (MPa), of the bolts in this new batch to ensure they meet strict safety specifications.

A.

The quality control department initially proposes the following investigative question: "Are the new bolts strong?"

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

B.

To collect data, a technician proposes testing the first 100 bolts produced by the manufacturing machine on a Monday morning.

Identify the sampling method proposed. Explain how this method could introduce bias into the estimate of the mean tensile strength of the entire batch, and state the likely direction of the bias.

C.

To avoid the bias identified in Part B, the department decides to use a stratified random sample. The batch of 10,000 bolts is produced across four different shifts (Morning, Afternoon, Evening, Night), with exactly 2,500 bolts produced per shift.

Describe a procedure the department could use to select a stratified random sample of 100 bolts using these four shifts. Explain one statistical advantage of using a stratified random sample over a simple random sample in this context.

D.

The stratified random sample is successfully implemented. The sample mean tensile strength is 940 MPa940 \text{ MPa}940 MPa with a standard deviation of 15 MPa15 \text{ MPa}15 MPa. The distribution of tensile strengths in the sample is approximately symmetric.

One bolt in the sample had a tensile strength of 892 MPa892 \text{ MPa}892 MPa. Calculate the z-score for this bolt's tensile strength and interpret it in context.

Timed

00:00

Response auto-saves
Pep

essential ap study content awaits..

Features
Testimonials
Testimonials
start studying →
FRQ Directions
Free Response Question Practice

This practice environment simulates the AP AP Statistics Free Response Questions section. Here are some guidelines:

  • Read each question carefully before responding. Pay attention to command verbs like "identify," "explain," "analyze," or "evaluate."
  • Use the timer to practice time management. You can pause, restart, or hide the timer as needed.
  • Mark for Review if you want to come back to a question later.
  • Your responses are saved automatically as you type. You can also use the drawing tool for questions that require diagrams or graphs.
  • Use the toolbar for formatting options like bold, italic, subscript, and superscript.
  • Navigate between questions using the Previous and Next buttons at the bottom of the screen.

Tip: Answer all parts of each question. Partial credit is often available, so even if you are unsure, provide what you know.