Main content

AP®︎/College Statistics

Unit 7: Lesson 4

Independent versus dependent events and the multiplication rule

Probability with general multiplication rule

AP.STATS: VAR‑4 (EU), VAR‑4.D (LO), VAR‑4.D.2 (EK), VAR‑4.E (LO), VAR‑4.E.1 (EK), VAR‑4.E.2 (EK) CCSS.Math: HSS.CP.A.2, HSS.CP.B.8

Google Classroom

You might need: Calculator

Rosalyn is a teacher who plays a review game with her class. The game involves writing each student's name on an identical slip of paper and selecting students at random. Here's the makeup of her class:

Grade	10, start superscript, start text, t, h, end text, end superscript	11, start superscript, start text, t, h, end text, end superscript	12, start superscript, start text, t, h, end text, end superscript
Number of students	7	18	5

Suppose that Rosalyn wants 2 different students, so she picks 2 names without replacing names between picks.

What is the probability that both students selected are 11, start superscript, start text, t, h, end text, end superscript graders?
Round your answer to two decimal places.

Stuck?

AP®︎/College Statistics

Unit 7: Lesson 4

Problem