Probability Trees and Discrete Variables (Q2a)

Here I solve a full Chapter 7 exam question.

First , I look at the language used in the question to identify which chapter’s techniques are appropriate. Once this is determined to be a discrete probability distribution problem, I use a probability tree (learned in Chapt.6) to find all possible outcomes as well as their probabilities in order to construct the Discrete Probability Distribution.

TIP » Using a Probability Tree to Get a Discrete Probability Distribution:

• Each pathway through the tree will lead to an outcome that can be represented as a value of (x) on the discrete random variable table.
• Add the joint probabilities of all outcomes with the same value of (x) to get the probability P(x) on the dicrete probability distribution table.