probability

  1. B

    Basic probability help

    Mechanical Engineering reported on the need for wireless networks to monitor the quality of industrial equipment. For example, consider Eaton Corp., a company that develops distribution products. Eaton estimates that 90% of the electrical switching devices it sells can monitor the quality of the...
  2. R

    Probability of throwing n different numbers in m throws of a dice

    Folks I know how to calculate the probability of throwing the same number in every throw of a dice (die, if you prefer!), and I know how to calculate the probability of throwing a different number in each throw of a dice. But how do I calculate the probability of throwing n different numbers...
  3. G

    Probability Question

    Hi Everyone, I'm looking to calculate the probability of the time taken for a specific event. I have: The best case scenario which normally takes 30 seconds and happens 90% of the time. The worst case scenario which normally takes 3 hours and happen the remaining 10% of the time...
  4. N

    Conditional Probability Problem Help!

    Hey guys, I got this question as a practice problem. I believe that it's a conditional probability where I should find the probability of NOT selecting one-half gallon carton. Can someone confirm if there is a typo in this question/is it solvable? Because it doesn't state the sample size to...
  5. F

    Gambler's ruin problem - modified

    Hi there, I'm a probability newbie. Can anyone help me with the following problem? A player begins with £1 and each round they can wager £1 on the outcome of a game. The player wins the game with probability p (0.48), in which case they get £1 in winnings and with probability 1-p (0.52)...
  6. 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...
  7. L

    Doing Probability through Excel

    Hi everyone! This is my first post here so I hope I am doing it correctly. So I have been given a piece of work from my university in regards to using Excel to conduct certain probability finding questions. I will write the questions below and show you what I have done so far in hopes for...
  8. U

    For the following example, is order meaningful or not?

    Consider a hypothetical example. There are 12 tickets for a documentary film and exactly 12 people to buy the tickets (one person can buy only one ticket). There are 3 ticketbooths for selling the tickets and each ticketbooth will sell exactly 4 tickets. Suppose the researcher labels the 12...
  9. R

    Bayesian exercise

    -2 down vote favorite I cant get my head round the following exercise: You are testing dice for a casino to make sure that sixes do not come up more frequently than expected. Because you do not want to manually roll dice all day, you design a machine to roll a die repeatedly and record the...
  10. W

    Normal Distribution

    Assuming that the number of marks scored by a candidate is normally distributed, find the mean and the standard deviation, if the number of first class students(60% or more marks) is 25, the number of failed students(less than 30%marks) is 90 and the total number of candidates appearing for the...
  11. B

    NCA Office Pool Win Probability

    Hello, I run a small NCAA office pool website where folks make predictions about the outcome of each game in a 64-team tournament that consists of six, single elimination rounds. Each correct prediction is worth a standard amount of points, and you compete in leagues against friends and...
  12. J

    Number of Possible Orders

    In a regional spelling bee, the 8 finalists consist of 3 boys and 5 girls. Find the number of sample points in the sample space S for the number of possible orders at the conclusion of the contest for: a) all 8 finalist. b) the first 3 positions. My solutions: a) 8! = 40,320 sample points...
  13. B

    Probability Q help, uses combinatorics, Poisson-Distr and possibly Multinomal

    Place successively and independent of each other 20 particles into 10 boxes. Hereby, each of the 10 boxes is chosen with the same probability. a) Determine the probability of the following events 1. Exactly one particle is in box 1. 2. At least one particle is in box 1. b) Give the...
  14. N

    Real life probability problem

    So I'm wondering if someone can solve this problem for me. Some work was done in our kitchen yesterday and the fridge had to be moved. I noticed some pretty bad scratches on the wood floor that were clearly from the fridge. The fridge hadn't been moved for 39 days prior. So what is the...
  15. M

    S1 Statistics question help! Majorly stuck

    Hi I have 3 statistics questions that I would like help with, 1. When Albert eats in a certain restaurant, he always eats either chicken or beef for his main course. And he always eats either sponge pudding or ice cream for his dessert. The probability that he eats chicken is 1/3, the...
  16. N

    What distribution is better in these situations?

    I'm new in statistics and probability and I'm a little lost about what distribution is better in these situations: If a tumor is malignant or not --> Bernouilli Number of entries in an emergency service during a night, know that on average 20 entries are observed per night. --> Poisson Tumor...
  17. G

    Probability of observing mean difference/compute ranksum

    Hi everyone, would appreciate some help on these three questions. If possible with calculations so that I can understand more easily! Suppose the endowment effect experiment were run with 5 people, 3 sellers and 2 buyers. Subjects arrive in the lab and pick numbers 1-5 out of the hat. If they...
  18. J

    Where did I go wrong in these three questions?

    Hi everyone, I just finished taking an online test and found out that some of my answers were wrong. The questions and answers can be found in attached screenshots. Question 1 (Suppose T and Z are random variables) https://s9.postimg.org/7krqdwirz/image.png I got no credit looks like it is...
  19. E

    Definition of random variable with respect to event space

    It is given that: We toss two dice with sample space Ω = {(i, j), 1 ≤ i, j ≤ 6} and the σ-algebra is generated by the events Ak = {(i,j) : max(i,j) = k} (k = 1, . . . , 6). Show that whereas X1(i, j) = max(i, j) is a random variable in the corresponding probability space, X2(i, j) = i + j is...
  20. S

    Conditional Monthly Risk Calibration for a trading model

    Hi, I have a trading system with a portfolio of assets (long and shorts) with daily market returns. I want to overlay a risk management to my trading system that calibrate my portfolio positions on a daily basis so that a monthly portfolio loss of lets say 20% only occurs 1% of the time...