distribution

  1. R

    Sample mean differs from population mean due to weighting

    Hi folks, The disclaimer first: I'm not primarily trained in statistics, so this problem might sound very naive to the experienced statisticians. Your expertise is what I'm looking for and any help is highly appreciated. Now the problem: I am supposed to calculate total chocolate consumption...
  2. D

    Distribution of fixed effects

    Hi all, Let me shortly introduce my research: I am looking at whether companies outperform each other in investments. To do this I observe them at multiple investments, and calculate fixed effects. Afterwards, I tested the fixed effects to confirm whether at least one company outperforms...
  3. M

    [R] Estimation of the emprical distribution

    Hi all, I was wondering if there's an R package online that automatically estimates the best distribution of my empirical data and gives the estimated parameters? I have a distribution that contains both positive and negative numbers. Cheers
  4. 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...
  5. A

    25th percentile of right-skewed and left-skewed distribution

    Hi All, Is it possible to have two lists of numbers with the same number of elements and same average, where one has a left-skewed distribution and the other has a right-skewed distribution and the 25h percentile of the numbers with the right-skewed distribution is smaller than the 25th...
  6. P

    binomial distribution problem, calculating probability from a B(p,q) distribution

    Hello everyone, I have been trying to solve this Beta distribution problem for quite some time without success. I can get as far as getting the 20 value, but I just cannot tell how the f(x)dx = .3672 is obtained. Underneath is a short description of the problem and on attachment the approach...
  7. K

    PDF of LogNormal distribution from random numbers

    Dear all, I have trouble understanding why "textbook" formula for probability density function (PDF) of lognormal distribution is different from results I got when I try to generate PDF using random data. So here is classic formula of lognormal PDF from Wikipedia with 1/x before...
  8. trinker

    Determine distribution and parameters

    I have a question but maybe it's the wrong question so I'll state the task first... I want to make data that looks like the data I'm working with without actually being the data itself. So I want to maintain structure as much as possible and generate an n row data set with similar...
  9. D

    Generating random data from correlations

    Say I have a list of personality traits: courage, materialism, compassion and so on. I interview some people and assign a rating from -10 to +10 to each trait for each person, then I find the correlation between each pair of traits. Now I want to create a "random person" by assigning a value...
  10. C

    Trying to calculate confidence intervals

    Hi everyone. The numbers below are the annual maintenance costs of a program I am working on. I'd like to use the data set to estimate future costs at different confidence intervals (e.g. 80%). Can you help me with what distribution would be best and how to produce a CDF that I can graph...
  11. K

    New Tax Concept

    Hello, I've been recently mulling over the systematic issues that seem to plague our current society. Primarily, income inequality. I'm a firm believer in capitalism and as such I wanted to find a solution to the income problem which worked with capitalism instead of against it. In...
  12. R

    Low within-scale variances leads to odd distribution

    Hello everyone: I'm a first time poster and I believe that this thread belongs in the General Stats topic, but feel free to correct me if you think it would have a better home under another topic. I have a nine-item measure with four response options. Across ~450 participants, ~180 had...
  13. P

    differential distribution frequency

    Hi there. pls I'm studying the production of energy from sawdust.So I need a firm grip in powder technology.Can anyone pls show me mathematically how the differential distribution frequency fm(D) was obtained in the attachment below. the data is from a published journal.Many thanks
  14. L

    Can I use a Negative Binomial Regression for a Continuous Outcome?

    Hello, My outcome is Sugar intake with a highly skewed continuous outcome variable. The histogram and variable details are Attached. Since the distribution is highly skewed and has a very high variance (12.78) compared to the mean (2.67) I thought I could round each decimal to the nearest...
  15. R

    Comparing means with Poisson distributed data?

    Hi everyone! How can I perform ANOVA, so to compare means, when the data of my groups are clearly Poisson distributed (towards 0 values)? Thanks a lot! Cheers
  16. trinker

    Show distributions, same height different variances

    I want show two distributions on the same pot that have identical height but different variances. I understand logically why my approach below doesn't result in equal heights. Now how can I force it to have equal heights. if (!require("pacman")) install.packages("pacman")...
  17. A

    Detecting Change in not Normally Distributed Count Data

    Hello, I was wondering if anyone could shed some light on how to interrogate count data whichholds a lot of 0'sand therefore not normally distributed. I have pasted in an example of the dataset i'm using. It gives 4 species counts across 27 sites (replicates) across intermittent years...
  18. A

    Aggregate Loss Model (Actuarial Science)

    Question: Let S be the random sum of N independent frequencies {{M_i}} where N is negative binomial distributed with r = 5 and \beta= 3 and {M_i} is Poisson distributed with  = 3. Find F_S(3) Attempt: I know the formulas for these two distribution, but I am totally lost of how I...
  19. hanialbarni

    How to test data if it is normal distribution in spss ?

    Hello Good morning guys i will need some help truly i have variables in spss most of them scale type, some of them are nominal, and few are ordinal. My questions how can i get the graph for normal distribution for the whole data ? shall i combine all scales into one variable and combine all...
  20. 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...