2019, Question 5 · 4 points
Phone battery life and warranty value
Use a normal model to find the time by which a quarter of batteries fail and the chance of failing within the warranty, then find the company's expected gain per warranty sold.
This exam had six free-response questions, each scored from 0 to 4. Its Question 6, the Investigative Task, is no longer part of the exam. The current exam has 4 free-response questions in 90 minutes. The skills these questions practice still count.
Lessons this question draws on
1 Read the question
The question is College Board's, from the 2019 exam. It starts on page 11 of the PDF. College Board no longer posts this exam, so it opens from the copy of College Board's PDF that the Internet Archive saved on March 15, 2026.
Open Question 5 (PDF, page 11)
2 Write your answer
Answer each part the way you would on the exam, in full sentences, with your work shown. Your writing saves as you type.
3 Score it
Score your answer against College Board's scoring guidelines, one point at a time. Give yourself a point only when your answer says what the guideline asks for.
Scoring guidelines (PDF, page 24) What the exam readers saw (Chief Reader report)
Question, scoring guidelines and Chief Reader report: College Board, from the Internet Archive. The title and summary are ours.