hypergeometric

  1. S

    Question on sampling without replacement

    Here is a question regarding sampling without replacement. Say there is a class size of 24, and the teacher is breaking students into groups of (4) for project work. The teacher selects the groups by putting all (24) names into a hat, then drawing (4) at a time. What is the probability that (2)...
  2. U

    probability for two replication

    Suppose that a sample of size n is to be chosen randomly (without replacement) from an urn containing N balls, of which m are white and N-m are black. If we let X denote the number of white balls selected, then the probability of getting exactly i white balls is...
  3. M

    Hypergeometric problem

    Hello everybody! :D I'm new to statistics and I'm struggling with a hypergeometric problem: Suppose I have a drawer with 100 socks in different colours, and suppose I know exactly how many of each colour there are. Now suppose I draw a handful of socks, say 10, at random. How do I calculate...
  4. S

    Hypergeometric distribution appears to have hidden problems

    When I was writing a computer program to calculate hypergeometric distributions probabilities I had some funny results. This is because I just used the condition I found in a stats book. The book says: p(x) = formula with x =0;1;....;n where n is the size of the sample drawn and p(x) = 0...
  5. F

    Hypergeometric distribution

    Hi, I hope you can help, i have an assignment i can not solve: You proffessor in sample theory think that their is 400 students 2 years ago, where 20 of them who smoke. Now their i made an research in my class, and out the 25 asked, 2 people said that they smoke. Assume that those 25...
  6. M

    Reaching a 95% Confidence level within an estimated population.

    How can I reach a 95% Confidence level after estimating the population size? I have a population of 367 products of which I have a sample of 50. Products can have a damaged package or can be damaged itself. We know for a fact that products can only be damaged if the package is damaged. From the...
  7. A

    Probability question

    I need a probability question answering as soon as possible and i though this might be the place to come. There are 13 balls in a hat being randomly drawn out one at a time. There are 4 green balls, 2 red balls and 7 black balls. A selection of 8 balls are randomly drawn. What is the...
  8. R

    Hypergeometric and Binomial Distributions

    Hi all, I am getting a bit confused with these two questions: 1. 20% of widgets are faulty previously. You receive a lot of 20 widgets. You have tested the first 6 and found that 2 are faulty and 4 are not. What is the probability that you will have at most 4 faulty widgets in the entire...
  9. W

    Lottery question

    Hey guys, new here. Just wondering if i am playing 23 games in a lottery, and IN TOTAL across the 23 games, the number 1 is drawn 9 times, what is the probability of that occurring? some more info about this specific game, there are 45 balls, and each game consists of 7 balls/numbers...
  10. A

    Fisher's exact test, Hypergeometric distribution

    Hi, I need some help with Fisher's exact test and the hypergeometric distribution My data consists of: 500 mutations - that I want to score as either damaging or benign 500 population allele frequencies (AF) - extracted, for each mutation, from a set of 10 000 controls For each...
  11. R

    Probability distribution function for extracting b balls out of a urn.

    Hello everybody, First of all I would like to say that I am not a student trying to get his homework solved. Rather I am a software developer trying to implement a game that has a probabilistic side... In case it makes any difference :D. The abstraction of the problem is pretty simple and...