2024, Question 4 · Focus on Probability and Sampling Distributions · 4 points
Opening geodes to find a red crystal
Find the mean and standard deviation of the wait for a first success, complete a probability distribution for a player who stops after at most four tries, and compute and interpret its mean.
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.
Not in the current course. Part (a) uses the geometric distribution, which the current course no longer includes.
1 Read the question
The question is College Board's, from the 2024 exam. It starts on page 9 of the PDF.
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 19) What the exam readers saw (Chief Reader report)
Question, scoring guidelines and Chief Reader report: College Board. The title and summary are ours.