Презентация Conditional Probabilities Statistical Independence. Week 6 (1) онлайн
На нашем сайте вы можете скачать и просмотреть онлайн доклад-презентацию на тему Conditional Probabilities Statistical Independence. Week 6 (1) абсолютно бесплатно. Урок-презентация на эту тему содержит всего 32 слайда. Все материалы созданы в программе PowerPoint и имеют формат ppt или же pptx. Материалы и темы для презентаций взяты из открытых источников и загружены их авторами, за качество и достоверность информации в них администрация сайта не отвечает, все права принадлежат их создателям. Если вы нашли то, что искали, отблагодарите авторов - поделитесь ссылкой в социальных сетях, а наш сайт добавьте в закладки.
Оцените презентацию от 1 до 5 баллов!
- Тип файла:ppt / pptx (powerpoint)
- Всего слайдов:32 слайда
- Для класса:1,2,3,4,5,6,7,8,9,10,11
- Размер файла:1.93 MB
- Просмотров:84
- Скачиваний:0
- Автор:неизвестен
Слайды и текст к этой презентации:
№1 слайд
Содержание слайда: BBA182 Applied Statistics
Week 6 (1) Conditional Probabilities
Statistical Independence
Dr Susanne Hansen Saral
Email: susanne.saral@okan.edu.tr
https://piazza.com/class/ixrj5mmox1u2t8?cid=4#
www.khanacademy.org
№2 слайд
Содержание слайда: Interpreting probability
No matter what method is used to assign probabilities, we interpret the probability, using the relative frequency approach for an infinite number of trails.
The probability is only an estimate (Turkish: tahmin), because the relative frequency approach defines probability as the “long-run” relative frequency.
The larger the number of observations the better the estimate will become.
Ex.: Tossing a coin
Head and tail will only occur 50 % in the long run
Computer simulations
№3 слайд
Содержание слайда:
№4 слайд
Содержание слайда:
№5 слайд
Содержание слайда: Definition of marginal probability
Represent the totals found in the margins of a contingency table:
Marginal probabilities
№6 слайд
Содержание слайда: Definition of joint events (AB)
Two events occur together : Joint probabilities
№7 слайд
Содержание слайда: The following contingency table shows opinion about global warming among U.S. adults, broken down by political party affiliation.
№8 слайд
Содержание слайда: A) What is the probability that a U.S. adult selected at random believes that global warming is a serious problem?
B) What type of probability did you find in part A? (marginal or joint probability)
C) What is the probability that a U.S. adult selected at random is a Republican and believes that global warming is a serious issue?
D) What type of probability did you find in part C? (marginal or joint probability)
№9 слайд
Содержание слайда: A) What is the probability that a U.S. adult selected at random believes that global warming is a serious problem? = = 63 %
B) What type of probability did you find in part A? (marginal or joint probability) Marginal probability
C) What is the probability that a U.S. adult selected at random is a Republican and believes that global warming is a serious issue? = = 18 %
D) What type of probability did you find in part C? Joint probability
№10 слайд
Содержание слайда: Conditional Probability
What if we were given the information that the selected person is a republican, instead of U.S. adult? Would that change the probability that the selected person’s opinion about global warming is a nonissue?
№11 слайд
Содержание слайда: Conditional Probability
№12 слайд
Содержание слайда: Conditional Probability
When we restrict our focus to republicans, we look only at the republican’s row of the table,
Which gives the conditional probability of opinion on Global warming “given” the person is republican.
№13 слайд
Содержание слайда: Conditional Probability
Of the 500 republicans, 290 of them say that global warming is not an issue.
We write the probability that a random selected persons believes that global warming is not an issue “given” the person is republican:
P(nonissuerepublican) = = 0.58 or 58 %
№14 слайд
Содержание слайда: Conditional Probability
If we now focus on democratic instead. Of the 500 democratic people only 85 say that global warming is a nonissue:
We write the probability that a random selected persons believes that global warming is not an issue “given” the person is democratic:
P(nonissuedemocratic) = = 0.17 or 17 %
№15 слайд
Содержание слайда: Conditional Probability
If we focus on “serious concern”: Of the 755 people who say that global warming is a serious concern 415 are democratic
We write the probability that a random selected person is democratic “given” the person is says global warming is a serious concern:
P(democratic serious concern) = = 0.549 or 55%
№16 слайд
Содержание слайда: Conditional Probability
P(nonissue |republican) = = = .58
№17 слайд
Содержание слайда: Conditional Probability
A conditional probability is the probability of one event, given that another event has already occurred:
№18 слайд
Содержание слайда: Conditional Probability - Example
What is the probability that a car has a CD player, given that it has AC ?
i.e., we want to find P(CD | AC)
№19 слайд
Содержание слайда: Conditional Probability Example
№20 слайд
Содержание слайда: Conditional Probability Example
№21 слайд
Содержание слайда: Conditional Probability – manufacturing example
1. What is the probability that the computer chip was delivered by Manufacturer B
given it was defective? P(B|D) =
2. What is the probability that the chip was satisfactory given it was delivered by
Manufacturer B? P(S|B) =
№22 слайд
Содержание слайда: Conditional Probability - example
1. What is the probability that the computer chip was delivered by Manufacturer B given it was defective? P(B|D) = = = 0.625 or 62.5 %
2. What is the probability that the chip was satisfactory given it was delivered by manufacturer B? P(S|B) = = = 0.9498 or 94.98 %
№23 слайд
Содержание слайда: Conditional Probability - example
1. What is the probability that the computer chip was delivered by Manufacturer A given it was defective? P(A|D) =
2. What is the probability that the chip was satisfactory given it was delivered by manufacturer A? P(S|A) =
№24 слайд
Содержание слайда: Conditional Probability - example
1. What is the probability that the computer chip was delivered by Manufacturer A given it was defective? P(A|D) = = = 0.375 or 37.5 %
2. What is the probability that the chip was satisfactory given it was delivered by manufacturer A? P(S|A) = = = .9800 or 98 %
№25 слайд
Содержание слайда: Class exercises
Discrimination in the workplace is illegal and companies that do so are often sued. The female professors at a large university recently sued the university, about the last round of promotions from assistant professor to associate professor:
An analysis of the relationship between gender and promotion produced the following probabilities:
№26 слайд
Содержание слайда: Class exercises
What is the probability of promotion given female assistant professors ?
What is the probability of promotion given male assistant professors?
Is it reasonable to accuse the university of gender difference?
№27 слайд
Содержание слайда: Class exercises (continued)
Solution:
P(promoted│female) = = = .2 or 20%
P(promoted│male) = = or 20 %
There is no reason to accuse the university for discrimination
№28 слайд
Содержание слайда: Statistical Independence
Two events are statistically independent if and only if:
Events A and B are independent when the probability of one event is not affected by the other event
If A and B are independent, then
№29 слайд
Содержание слайда: Statistical independence
From our previous example about global warming:
Is saying: Global warming is not an issue, independent of the political party the person is a member of?
We need to check: If the P(nonissue|republican) = P(nonissue) ?
P(nonissue|republican) = = = .57 P(nonissue) = .37
P(nonissue|republican) P(nonissue), therefore the events are not independent
№30 слайд
Содержание слайда: Statistical Independence
Car example
№31 слайд
Содержание слайда: Class exercise Independent-dependent events
Determine whether the event A3 and B2 are independent or dependent events. P(A3|B2) = P(A3)?
Determine whether the events B1 and A1 are independent or dependent events. P(A1|B1) =P(A1)?
№32 слайд
Содержание слайда: Solution:
P = = 0.25 P(A3) = 0.2 P P(A3) They are dependent events
P(A1 = = = 0.5 P(A1) = .4 P(A1 P(A1) They are dependent event
In general, if one combination of events is independent (or dependent) then the other combinations in the table are independent (or dependent).
Скачать все slide презентации Conditional Probabilities Statistical Independence. Week 6 (1) одним архивом:
