poisson distribution

  1. S

    Disrete Probability and Poisson distribution

    1. You roll 7 dice at once. Find the probability that 2 of them will roll more than 2. Answer: 3.84% 2. On average, 2 major earthquakes with a magnitude of 8 or more occur each year. Calculate the probability of 11 major earthquakes happening during 3 years. Answer: 2.25% Please, help to...
  2. S

    Finding Variance in Poisson distribution question

    Hello! Can anyone tell me how to solve this question? Consider that X~ Poisson(μ) and P(X > 0) = e ^−1.5 Find the variance? I need P(x =0) to use the formulae of Poisson distribution. But I don't have that!
  3. D

    How do I test if my data is Poisson Distributed?

    I'm unsure as to what the correct way is to calculate Pearson's Chi-Squared statistic from my data to then test if it is Poisson distributed. (I'm working in RStudio) Here is my data: > X [1] 70 60 60 57 100 100 75 60 65 70 120 60 65 60 80 90 65 80 75 75 100 65 90 60 150...
  4. S

    Binomial/Poisson (or any ) Distribution for finding out probability of me getting into a business school,plz help with my calculation.

    Probability of getting into a business school is 10%,I have applied to 12 business schools,what is probability that i get accepted by atleast 1 of them? My solution as per Binomial Distribution:- Probability of success(p)=1/10...
  5. H

    correcting with poisson regression

    Hi everyone, I'm new to stats and I was wondering if anyone had any good resources that could explain to me: How one can correct their data (false-positives) using poisson-regression. I've been looking for some resources to explain it simply and give a step by step (in r ) but I've had...
  6. A

    Can I use a Poisson distribution for non-normal binomial data?

    Hello all. I'm working on the following question: Fifteen percent of the items produced by a machine are defective. Out of 15 items chosen at random, a)what is the probability that exactly 3 items will be non-defective? Now this is a binomial distribution but; pn = 85/100 (15) = 12.75 and qn =...
  7. J

    poisson distribition question

    Hello everyone, I don't really understand the answer of question a. The question was: Find the probability that on any given day there will be fewer than two breakdowns on this highwayduring the morning rush hour. Additional information: on average: 3,2 breakdowns per day occur. isn't it...
  8. N

    Determining how to find the prob. an event will occur between 2 yrs. (Poisson dist.)

    Hello! I am having trouble with the following question regarding the Poisson distribution. I was thinking that lambda is (2.5/100)(25). I'm not really sure if this question relates to the exponential distribution or Poisson distribution because of the fact that it asks for the probability the...
  9. Q

    P values from 95% CI using poisson distribution

    Hi, Hope I'm in the best place for an answer :) I have a study across 10 years. I have an incidence rate that was calculated for each year along with the 95% confidence interval using a Poisson distribution. My question is how do a get p-values for pairwise comparisons? I understand I can say...
  10. J

    Distribution of Data

    Hello forum members, I wonder if someone can kindly help. I have a dataset which I've uploaded and I'm trying to work out a sensible distribution. It represents the number of throws a darts player needs before he can aim for a double. The minimum possible is 8 and the maximum possible is...
  11. L

    poisson distribution example

    If the mean rate of arrival in a restaurant is 10 customers per hour, what is the probability of having 4 customers arriving in any hour? P(4) =10ˆ4 eˆ-10 / 4! = 0.0000454 X 10000/24 =0,0189 but 0.0000454 this number seem wrong for me and if we reduce the arrival on 10 minutes we...
  12. W

    Link = log code won't work

    Hi, doing a generalised linear model with poisson distribution, here is my model code... model<-glm(carnivore_abundance~altitude_1+dist_stream+canopy_openess+basal_area+dist_large_river,family=poisson,data=main_data) really frustratingly whenever I try to add link=log is doesn't work it...
  13. S

    'e' in expected values in Poisson

    Using this example (see below) could someone please tell me what the 'e' symbol stands for and how one would work out the expected values manually. 'log(λi) = 1.65 + 0.43 × xi where xi = 1 for a female, and xi = 0 for a male. Poisson Regression Using this example, we see that for a...
  14. K

    Probability of a Poisson Distribution without t given problem

    This is on my final exam study guide for statistics. I have absolutely no idea how to do it Problem 1: Valerie Variance is taking her "no-time limit " final exam. As always, the exam has an infinite number of questions and the instructor gives no partial credit. Valerie being a diligent...
  15. I

    Poisson Distribution using probabilities

    If X follows a poisson distribution where P(X=1)=0.4,P(X=2)=0.6, what is the value of P(X=0)? How will I solve this question?
  16. C

    How does "qpois(1-pvars, 3, .25) " work in R ?

    R code : library(MASS) mu <- rep(0,4) Sigma <- matrix(.7, nrow=4, ncol=4) + diag(4)*.3 rawvars <- mvrnorm(n=10000, mu=mu, Sigma=Sigma) pvars <- pnorm(rawvars) binomvars <- qpois(1-pvars, 3, .25) I have not understood how does qpois(1-pvars, 3, .25) work ? What is the...
  17. Q

    Hypothesis Testing Help

    Hello fellow statisticians! it's been awhile since I've done stats and everything has completely escaped me. I'm trying to conduct hypothesis testing for the question below. Everyone has been using the Chi-squared test and I feel that they are wrong. I think it should be a poisson distribution...
  18. J

    Is this variable following a poisson distribution or a binomial distribution?

    You're at a bus stop watching people go by, not buses. Let X = number of people wearing headphones
  19. A

    Poisson Distribution with two different expected value

    Question: Suppose there are number of accidents at location A and location B each day with Poisson Distribution with rate 0.001 and the number of patients during each accident is Poisson distributed with rate 0.1. Find the probability that the number of patients less than 3 in one day...
  20. P

    Bycatch of dolphins data, zero inflated and under-dispersed - what next?

    I am investigating the factors that influence the bycatch of dolphins using a poisson GLM. My response variable is bycatch rate per unit effort and varies from 0 to 0.125. However, my response is very zero-inflated (2304 of 2436 observations are zero). I have three response variables (two...