joint probability

  1. N

    joint probability distributions

    Hi, I am very puzzled as to how they achieved μ=2/5 in the example below. I understand that μ is just expected value which would mean summing x or y with its possible realizations. I'm thinking this is very obvious, however, I just can't see how they arrived at 2/5, which just proves I...
  2. D

    The proportion of twitter followers of handle X also following Y

    OK, someone recently asked me what the probability that followers of Twitter handle X are also followers of Twitter handle Y. I used some R code (using the twitteR package) to get 47,000 followers from X and 61,000 followers of Y (the two handles have a LOT of followers). I created a vector and...
  3. J

    joint probability

    I am not really sure how to calculate question C. Can anyone help me out? Thanks in advance!
  4. M

    Joint Probability

    Hi All, I'm currently in a grad course with a nice complement of stats which we have been tasked to learn ourselves. Having some difficulties understanding joint probabilities. Specifically, I have a problem where we have 3 possible outcomes with probabilities p1=0.4, p2=0.1 and p3=0.5. If we...
  5. X

    joint probability with conditional

    Hello, What is P(A|B, C)? I have a dataset and I want to estimate the mutual information of A|B and C. The formula for mutual information is Sum_A|B Sum_C p(a|b, c) log( p(a|b, c) / p(a|b) p(b) ) da db I'm looking for a formula for p(a|b, c) Many thanks in advance Xavier
  6. S

    integrating joint probability distribution

    Hi, could you help me in compute the integral with respect to x of f(x,y)d(x,y) where f(x,y) is a joint probability distribution? I know that the integral with respect to x of f(x,y)dx is just f(y) where f(y) is the marginal distribution of y, but in the exercise I have f(x,y)d(x,y) inside the...
  7. Y

    Difference between p(y=0|x=0) and p(x=0,y=0)

    Another Trivial question: I have been asked to calculate the joint probability i.e. p(X=0,Y=0) and i have been provided by P(Y=0|X=0), is it the same?
  8. M

    What is joint probability of these events?

    We have two events A and B and three locations X, Y, Z. Each event A and B is carried independently on locations X, Y, Z. The individual probability of events A and B on all three locations is as following. ......X...............Y............. Z A...(0.25).....(0.40).....(0.15)...
  9. M

    Probability: Conditional Vs. Joint Issue

    Hi all, Brand new to this site. I've read the posting rules, but please feel free to herd me into the correct way of doing things with this community. I am dealing with this problem below. If you can see where my thinking is going awry, feel free to talk to me like a little kid. I...
  10. C

    Problem with calculate joint probability

    Hello I have a problem with calculating joint probabilities in text mining. i have two paralel text like this for example Bonjour les bons amis ----------------------------- good morning good friends My question is how to calculate p(Bonjour, good) ?? Any idea pliiiz...
  11. M

    max sum

    Consider two discrete variables x and y each having three possible states, for example x, y ∈ { 0, 1, 2 } . Construct a joint distribution p(x, y) over these variables having the property that the value  xi that maximizes the marginal p(x), along with the value  yi that maximizes the...
  12. S

    Joint Probability Issues

    I'm trying to prepare for a test and going over some practice problems I just found with no solutions, and they've basically led me to believe I'm completely lost. The section we're working on is joint probability, while the entire section in the book focused on problems with pdf's given as...
  13. U

    Joint probability distribution question help

    I attach image file of the problem. I hope you will help me.