13.6 Conditional Probability Models.notebook
May 14, 2014
Unit 12: Probability and Statistics
13.6 Conditional Probability Formulas
Conditional
Probability
Formula:
P(B A) =
P(A and B)
P(A)
13.6 Conditional Probability Models.notebook
Conditional Probability Examples:
1) P(increased sales attend seminar)
2) P(no increase sales
did not attend seminar)
May 14, 2014
13.6 Conditional Probability Models.notebook
May 14, 2014
Using Conditional Probabilities:
In a study designed to test the effectiveness of a new drug, half of the volunteers received the drug. The other half of the volunteers received a placebo. The probability of a volunteer receiving the drug and getting well was 45%. What is the probability of someone getting well, given that he receives the drug?
13.6 Conditional Probability Models.notebook
May 14, 2014
Using Conditional Probabilities:
A minor league baseball team starts one third of the players on their roster. If the probability that a player starts in minor league and makes it to major league is 18%, what is the conditional probability of a player making it to major league given that they start on their minor league team?
13.6 Conditional Probability Models.notebook
May 14, 2014
Example:
In a survey of pet owners, 45% own a dog, 27% own a cat, and 12%
own both a dog and cat. The same survey showed that 5% of pet
owners own a dog, cat, and another type of animal.
What is the conditional probability that a dog owner also owns a cat?
What is the conditional probability that a cat owner also owns a dog?
13.6 Conditional Probability Models.notebook
May 14, 2014
Example:
In a survey of pet owners, 45% own a dog, 27% own a cat, and 12%
own both a dog and cat. The same survey showed that 5% of pet
owners own a dog, cat, and another type of animal.
What is the conditional probability that a pet owner owns a cat and some other
type of animal, given that they own a dog?
What is the conditional probability that a pet owner owns a dog and some other
type of animal, given that they own a cat?
13.6 Conditional Probability Models.notebook
May 14, 2014
Using a Tree Diagram:
A soccer team wins 65% of its games on muddy fields and 30% of
their games on dry fields. The probability of the field being muddy for
their next game is 70%.
What is the probability that the team will win their next game?
13.6 Conditional Probability Models.notebook
May 14, 2014
You Try:
Suppose that a basketball team has a 75% chance of winning a
tournament if their star player is able to play. Otherwise, the team has
a 40% chance of winning the tournament. The doctor says the star
player has a 60% chance of being able to play.
What is the probability that the team will win the tournament?
13.6 Conditional Probability Models.notebook
May 14, 2014