A community for students.
Here's the question you clicked on:
 0 viewing
anonymous
 4 years ago
Event A and B are independent of each other...
What does independent mean here? How would it change if it said dependent. The full question continues as:
The probability of event A occurring is 3x as likely as event B occurring. The probability that neither event A nor event B will occur is 7/27. What is the probability of event A occurring?
anonymous
 4 years ago
Event A and B are independent of each other... What does independent mean here? How would it change if it said dependent. The full question continues as: The probability of event A occurring is 3x as likely as event B occurring. The probability that neither event A nor event B will occur is 7/27. What is the probability of event A occurring?

This Question is Closed

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0If two events A and B are independant then P(A intersection B)=P(A)P(B)

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0Just take P(B) as x P(A)=3x. Apply the condition and solve for x.

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0phi the venn diagram i think is wrong, independant does not mean that it has no element in common.

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.01P(A union B)=7/27. P(A union B)=20/27. P(A)+P(B)P(A intersection B)=20/27. x+3x3x^2=20/27. Solve for x.

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0@Phi, 15/27 is not a possible answer. Neither of you are making very much sense. I don't understand what shank means by intersection or union

Directrix
 4 years ago
Best ResponseYou've already chosen the best response.0Definition: Two events, A and B, are independent if the fact that A occurs does not affect the probability of B occurring. Some other examples of independent events are: Landing on heads after tossing a coin AND rolling a 5 on a single 6sided die. Choosing a marble from a jar AND landing on heads after tossing a coin. Choosing a 3 from a deck of cards, replacing it, AND then choosing an ace as the second card. Rolling a 4 on a single 6sided die, AND then rolling a 1 on a second roll of the die. http://www.mathgoodies.com/lessons/vol6/independent_events.html

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0Thanks directrix. Could you give some examples of dependent then?

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0how can you have a union or intersection of a probability? I thought that was in sets.

phi
 4 years ago
Best ResponseYou've already chosen the best response.1dw:1328149905682:dw shankvee definitely has the right idea here

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0The picture means nothing to me because I have no idea what you are talking about in the first place. Please look at my last inquiry that asked what union and intersection of probability is.

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0Please don't give up on me. I'm getting frustrated with this problem...

phi
 4 years ago
Best ResponseYou've already chosen the best response.1maybe sat can add some insight??

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0I wish asnaseer was here. Do you know him?

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0Could you at least tell me what intersection and union are? I know what they are in sets but I don't see how it can relate to probability.

phi
 4 years ago
Best ResponseYou've already chosen the best response.1I think of it this way. You have a universe of events (that is the box) which adds up to 1 events are regions of the universe. Here's a short write up http://www.stat.yale.edu/Courses/199798/101/probint.htm

phi
 4 years ago
Best ResponseYou've already chosen the best response.1Here is a simple example equal number of boys and girls in school probability of selecting girl if 1/2 some students play tennis, some play chess the students who play tennis overlap with boys and girls what's the probability of choosing a student who plays chess and plays tennis a venn diagram helps you visualize the problem dw:1328150687630:dw

phi
 4 years ago
Best ResponseYou've already chosen the best response.1btw, prob of A occurring is 2/3

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0I still don't understand how that helps me. Back to the wording of the original problem; probability of a is 3x as likely as b occurring so I did a = 3b but how do i write "The probability that neither event A nor event B will occur is 7/27" in an equation so that i can do systems?

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0your answer is correct. but i dont see how you got it, I'm not one where drawing a picture to explain your words helps much. Sure if I have a trig problem I'll draw the triangle out, but that is just to remember what the sides or angles are in relation to one another.

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0what is a disjoint event, the example it gives contradicts its definition because it says when two events have no outcomes in common the events are disjoint, but the example it gives only has one event and it says it is disjoint. To what?

phi
 4 years ago
Best ResponseYou've already chosen the best response.1"neither event A nor event B will occur is 7/27" means that A, B, or both occur 20/27 times Prob (A) + Prob(B)  Prob( both A and B) = 3b + b  b*3b where the x*3x comes from the statement that A and B are independent. As pointed out above, independent means Prob(A and B) = P(A)*P(B)= 3b*b= 3b^2

phi
 4 years ago
Best ResponseYou've already chosen the best response.1we subtract Prob(both A and B) because we would be double counting if we don't

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0so does P(A) + P(B) = 20/27?

phi
 4 years ago
Best ResponseYou've already chosen the best response.1almost. if your were counting tennis players and chess players it would add up correctly. But if someone plays both chess and tennis you have to subtract the double counting. so Prob (A) + Prob(B)  Prob( both A and B) = 20/27

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0I see. And the probability of A and B is like saying what is the probability of this happening and then this happening. So it would be mutliplication of the two probabilities?

phi
 4 years ago
Best ResponseYou've already chosen the best response.1yes. I think events are "randomly pick" out of the universe. what's the probability of selecting something out of the A box or B box. And somethings can be in both.

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0so say 1/4 prob. of someone in chess, and 1/5 prob. someone in tennis you would do 1/4 + 1/5 = 9/20  1/20 = 8/20?

phi
 4 years ago
Best ResponseYou've already chosen the best response.1if they are independent, which is a reasonable assumption.

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0what about if they were dependent, how would that change, what does that really even mean?

phi
 4 years ago
Best ResponseYou've already chosen the best response.1Dependent means the probability of event B changes (depends) on event A occurring

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0so now we have P(A) = P(3B) and P(A or B)  P(A and B) = 20/27 right? This is the same as P(3B or B)  P(3B and B) = P(3B) + P(B)  P(3B^2) = 20/27 Where do we go from here?

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.03B^2  4B + 20/27 = 0?

anonymous
 4 years ago
Best ResponseYou've already chosen the best response.0With that we get 10/9 and 2/9. 10/9 is impossible so it has to be 2/9 which is the probability of B occurring. Since A = 3B then A = 3 x 2/9 = 6/9 = 2/3!!!!!! I got the answer!!! Thank you thank you thank you thank you!

phi
 4 years ago
Best ResponseYou've already chosen the best response.1thanks, but I'm learning this too...
Ask your own question
Sign UpFind more explanations on OpenStudy
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.