1. 13.5 Conditional Probability
Find the probability of an event given the occurrence of another event.

2. Conditional Probability
The probability of an event under the condition that some preceding event has occurred.
𝑃 𝐴 𝐵 = 𝑃(𝐴 𝑎𝑛𝑑 𝐵) 𝑃(𝐵) 𝑤ℎ𝑒𝑟𝑒 𝑃(𝐵)≠0
1) Vanessa tosses three coins. What is the probability that she has tossed 2 heads, given that she has tossed at least 1 head?

3. 2) The table below provides some information about the ages of the first 42 US presidents at inauguration and their birth states.
What is the probability that a president was inaugurated at the age of 60 years or older, given that the president was born in Virginia?
Birth State
Under 60
60 and Over
Virginia 6 2
All other 26 8

4. 3) A 20 sided die has the numerals 1 through 20 on its faces
3) A 20 sided die has the numerals 1 through 20 on its faces. The die is rolled once, and the number on the top face is recorded. What is the probability that the number is a multiple of 3 if it is known that it is odd?
4) Kylie is conducting a survey of families with two pets. The pets could be 2 cats, 2 dogs or one of each. If a family is selected at random, what is the probability that the family will have exactly 2 cats if the second pet is a cat?

5. Guided Practice P