Bayes' Theorem: Probability of 8 Heads in 10 Tosses?

In summary, Bayes theorem is a mathematical formula used to calculate the probability of an event based on prior knowledge. It is commonly used in science, such as in medical diagnosis, to make predictions and decisions based on uncertain information. The assumptions of Bayes theorem include the independence of events and the completeness of the sample space. Unlike other statistical methods, Bayes theorem allows for the incorporation of new information as it becomes available.
  • #1
Tajeshwar
11
0

Homework Statement



Suppose I have a bent coin with a 60% probability of coming up heads. I throw the coin ten times and it comes up heads 8 times.

What is the value of the “likelihood” term in Bayes’ Theorem -- the conditional probability of the data given the parameter.


Homework Equations

The Attempt at a Solution



My attempt was 8 heads in a row should be (.6)^8... That comes to .0167. However, that is not one of the choices.

#4 almost matches, but there is a difference in the decimal.

The answer choices are:

0.120932
0.122885
0.168835
0.043945

[/B]
 
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  • #2
The question is not asking you for the probability for the coin to comu up heads 8 times in a row. It is asking you for the probability for it to come up heas 8 times in 10 tosses.
 
  • #3
Tajeshwar said:

Homework Statement



Suppose I have a bent coin with a 60% probability of coming up heads. I throw the coin ten times and it comes up heads 8 times.

What is the value of the “likelihood” term in Bayes’ Theorem -- the conditional probability of the data given the parameter.


Homework Equations

The Attempt at a Solution



My attempt was 8 heads in a row should be (.6)^8... That comes to .0167. However, that is not one of the choices.

#4 almost matches, but there is a difference in the decimal.

The answer choices are:

0.120932
0.122885
0.168835
0.043945
[/B]
(1) Please stop using bold font; it looks like you are yelling at us.
(2) There are many "sample points" in the event "E = {8 heads in 10 tosses}"; for example, three possible outcomes in E would be HHHHHHHHTT or TTHHHHHHHH or THTHHHHHHH, and there are several others as well. To get the probability of 8 heads you need to compute each such probability and then add them all up! There is a very familiar probability distribution associated with such problems, and you can very likely get a lot of relevant information by reading your textbook or course notes. Google is your friend as well.
 
  • #4
Ray Vickson said:
(1) Please stop using bold font; it looks like you are yelling at us.
(2) There are many "sample points" in the event "E = {8 heads in 10 tosses}"; for example, three possible outcomes in E would be HHHHHHHHTT or TTHHHHHHHH or THTHHHHHHH, and there are several others as well. To get the probability of 8 heads you need to compute each such probability and then add them all up! There is a very familiar probability distribution associated with such problems, and you can very likely get a lot of relevant information by reading your textbook or course notes. Google is your friend as well.

Sorry about the bold font. I did not realize that was offensive or I was even doing it. Thank you for pointing it out.

I also appreciate your guidance on this question.

I tried the binomial theorem for exactly 8 heads and that has led me to one of the choices. So that is what they must be asking. Let me see if it works out.

I think the general level of people on this forum is quite advanced and that is why my questions may seem a little too simplistic. Hopefully, I will keep learning and get there slowly.
 
  • #5
Orodruin said:
The question is not asking you for the probability for the coin to comu up heads 8 times in a row. It is asking you for the probability for it to come up heas 8 times in 10 tosses.

Yes thank you. That helped. Appreciate your guidance.
 

FAQ: Bayes' Theorem: Probability of 8 Heads in 10 Tosses?

1. What is Bayes Theorem?

Bayes theorem is a mathematical formula that helps calculate the probability of an event occurring based on prior knowledge or information. It is named after Reverend Thomas Bayes, an 18th century statistician.

2. How is Bayes Theorem used in science?

Bayes theorem is used in science to update the probability of a hypothesis or event as more evidence or data is gathered. It is used in fields such as biology, psychology, and medicine to make predictions and decisions based on uncertain information.

3. Can you provide an example of Bayes Theorem in action?

One example of Bayes theorem in action is in medical diagnosis. A doctor may use Bayes theorem to calculate the probability of a patient having a certain disease based on their symptoms, medical history, and test results.

4. What are the assumptions of Bayes Theorem?

The assumptions of Bayes theorem include the independence of events, the completeness of the sample space, and the accuracy of prior information. It also assumes that the probabilities of events do not change over time and that all relevant information is included in the calculation.

5. How does Bayes Theorem differ from other statistical methods?

Bayes theorem differs from other statistical methods in that it uses prior knowledge or information to update the probability of an event, rather than solely relying on observed data. It also allows for the incorporation of new information as it becomes available, making it a useful tool for decision making in uncertain situations.

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