1. E

    SAS glimmix overdispersion

    Let's say I have an experiment with a total of 10 petridishes each with 20 seeds. 5 of these petri dishes are variety A and 5 are variety B. I count the number of germinated seeds in each dish. There seems to be to be two main ways to model potential over dispersion: proc glimmix data=a...
  2. S

    Probability of boxers winning in 10,50,100 matches. Binomial

    In the final match a boxer is facing another boxer and is expected to win 48% of the time. In reality they win 80% of the time. What is the probability of that occurring in 10 matches? 2) In the very next match (in a different tournament), the boxer who won the previous match only wins 40% of...
  3. K

    (A Possible) Pooled P-Test Problem

    Historical data shows that 4% of the components produced at a certain manufacturing facility are defective. A particularly harsh labor dispute has recently been concluded, and management is curious about whether it will result in any change in this figure of 4%. A random sample of 500 items...
  4. N

    What is the smallest value of r that gives a test of size not exceeding 0.05?

    0down votefavorite I've been given a question that I don't understand. Question: Consider a test which rejects H0 if the number of observed successes is ≥r≥r , where r is some number. What is the smallest value of r that gives a test of size not exceeding 0.05? We have been given: o=50 ,for...
  5. Y

    Probability question

    The govt. of ontario decided it would try to raise money by installing photo radar cameras on the 401 highway acros the top of Toronto. The camera would be set to record the speed of those travelling more that 135 km/h and send them a ticket for $200. It would only run the program between the...
  6. A

    Binomial expectation E(X|X>1)

    General case: X~B(n,p) I could integrate the product of x and pmf from 1 to infinity and divide it by the integral of just pmf from 1 to infinity to find it, but I'm really stuck since I can't do it due to the sophisticated pmf function of binomial. How can we find this expectation and...
  7. N

    1-sample binomial for my research data?

    Hi, Newbie here so I will try to explain as clearly as I can. I do research in the neuro field. I have a control group of neurons that I am analyzing for the presence or absence (binary) of a specific trait (let's call it trait A). I found that the control group have A 60% of the time. Now I...
  8. P

    Assume that radon measurements are normally distributed

    with mean 4.1 and standard deviation 0.2. -Find the median of the measurement? -What is the probability the radon measurements exceed 4.5 picocuries?
  9. A

    Estimation of suitable significance level for high numbers of experiments

    I am a scientist and work with high numbers of experiments. For example: I have tested 1000 different parameters between 2 groups. I found 10 parameters, which are significantly different between the tested groups with a significance level of 5%. For only 1 tested parameter it would be...
  10. K

    Correlation betweeen k binomial variables

    Hello, This is my first post as a new member, so hope I'm posting this in the right place... I need a general formula to calculate the minimum sample size N required to determine whether k binomial variables are somehow correlated (either positively or negatively) at significance level p<=...
  11. S

    Poisson and binomial distributions

    I composed this question: A hospital has 20 ambulances and on average 2 break down a day. There are five ambulances in reserve and if more then five ambulances break down in a day there are problems. What is the probability that in a 30 day period there will be problems? My approach is this: I...
  12. J

    Binomial Random Variables

    Hey guys! I'm having some real trouble with these questions. Any help would be greatly appreciated! Thanks in advance (: 1.) A baseball player has a lifetime batting average of 0.183. If, in a season, this player has 250 "at bats", what is the probability he gets 29 or more hits? Probability...
  13. E

    Syntax and formula for the 99% confidence interval for a proportion

    According to: The 99% confidence interval for 23 out of 125 is: +-8.93, where observed proportion is 23/125=18.4%. When I try and replicate this in Stata, with reference to this...
  14. L

    If anyone can help please!! In DESPERATE need of clarification!

    Hi Everyone This is my first time on the site. Basically I am conducting some research for a dissertation I have to do as part of my course. I will be investigating whether a variety of drinks thickened using powder thickeners changes over the period of one hour. I have already conducted...
  15. I

    Normal Approximation to the binomial

    I'm trying to calculate the probability that there are greater than 300 successes from a pool of 1000 trials. I am told to use the normal approximation to the binomial and this is where is gets confusing. I have tried calculating the standard dev using =SQRT((100*0.3)*(1-0.3)). I am on the right...
  16. S

    Required sample size to distinguish means of two binomially distributed rv

    Hello, Currently trying to work out the best way to calculate the number of samples that would be required to get a certain confidence interval. If I have two binomially distributed data sets, which I predict to have some probability of an event p_1 and p_2. If I were to estimate p_1...
  17. B

    Hard probability question/game-binomial dist.

    Consider 50 people and series of 10 rooms. Each room has, for example, 5 doors that will open to the next room with known (totally known, including in later rooms), but different probabilities. Everyone begins in room 1, and each person selects a door. If that door opens, all of the people...
  18. A

    Binomial response variable with 3 continuous and 1 categorical predictor. Best test?

    Hello I have a binomial response variable. Predictors are composed of 3 continuous variables (the results of a Principle Components Analysis of habitat structure variables) and 1 categorical variable (habitat type e.g. grazed or ungrazed). I want to test whether the 3 habitat variables have...
  19. C

    Need help starting this question; unable to identify what type of question it is

    I can't tell if its asking for a binomial distribution or a normal probability distribution.. or maybe an approximation of a binomial distribution using a normal distribution..but then where does a random variable come in? here is the question: A company that manufactures mufflers for cars...
  20. A

    Negative Binomial Distribution

    Hi, Regards