chi square

  1. J

    Cumulants of non central chi-square distribution

    Cumulant generating function is defined by logarithm of Moment generating function. K_X(t)=\log M_X(t) let X is a non central \chi^2 variate with parameters degrees of freedom,n and non-centrality parameter,\lambda. Moment generating function of X is...
  2. J

    An Exercise of noncentral [math]\chi^2[\math] distribution.

    An Exercise of noncentral chi-square distribution. Let Y_1,\ldots,Y_n be independent random variables with Y_k distributed as N\sim(a_k,\sigma^2) , and \bar Y=\sum_{k=1}^{n}\frac{Y_k}{n} denote the sample mean, S^2 denotes the sample variance. Then show that...
  3. D

    need some help

    Hello, I need some help with this task: The price at which buyers are willing to pay for a book subdivided by chi square distribution with an unknown parameter k. 18 out of 118 customers bought book For £ 20. And I need to evaluate the unknown distribution parameter k. I would appreciate...
  4. P

    How do I interpret chi square goodness of fit results in R?

    I am a newbe in research and using R. I had to calculate the chi square to determine goodess of fit and I don't know how to interpret the results. Below is the results from R. Model Chisquare=2.060748 Df=2 Pr(>Chisq)=0.3568734 What does this mean and how do I interpret?
  5. S

    Likert Type Questionnaire Analysis.

    Hi everyone, any help you can offer me with my stats would be so greatly appreciated! Everytime i think i've worked it out, i end up confusing myself even more! Okay, my research is looking into whether perceptions differ both between male or female offenders across how they are related to...
  6. D

    Chi Square, Likert Scale, and Within Group - reasoning

    I am hoping some really smart folks can answer this question for me and provide some sage and learned advice to help me finish the last piece of my PhD dissertation research. Background: I have completed a data study, using a Likert Scale (1-5), on importance of an element within an...
  7. S

    Goodness-of-fit of model derived from multivariate logistic regression

    I have a question regarding the relationship between the value of Chi square and df in determining the goodness-of-fit in a model derived from multivariate logistic regression. If the N= 290, Chi square =26.57, p=0.003 in a model with 16 variables (df is not reported), can one tell if this is...
  8. T

    Chi-square, expected counts & Fischer exact test

    Sitting here with a stat book and some questions are popping up. Chi-square assumes that expected counts are greater than 5. However, in larger tables it is allowed to have up to 20% of expected counts less than 5. What is this 20% of? Is it of the cells in the matrix. For example, in a 2x4...
  9. T

    Pearson's chi-test for more than 2x2

    So, I have one stat book (Discovering Statistics by Andy Field; great book) that discusses Pearson's chi-test and how it's only applicable to a 2x2 contingency table with categorical data. The solution is to use the loglinear analysis for larger tables according to Andy. Another book I have...
  10. G

    Chi Square Test For Independence with Likert Scale

    Hello, I would like to do a Chi square test for independence with a Likert scale to see if there are any associations in gender and education level with regards to ethical consumption. Each question of my likert scale has 5 categories (definitely wouldn't buy it, wouldn't buy it, might buy...
  11. V

    Is a chi-square test appropriate? Can I make a more comprehensive analysis?

    Hi There, I am new to the research field, and I am currently trying to find a way to apporpriately analyze some data that I have collected. I am working in the biological sciences, and have read through the pages of suggested tests at http://udel.edu/~mcdonald/statchiind.html - which was...
  12. E

    Statistical Analysis Plan - help!

    I'm doing a summer research project on trends of anxiety and depression. Unfortunately, my preceptor has disappeared in the meantime and I'm left to fend for myself. I've done an extensive literature review, and now have to develop a Statistical Analysis Plan (SAP). While I understand that there...
  13. S

    Stratifying data with chi square analyses

    Hi I've carried out a study where 26 participants had to make decisions about 20 scenarios (i.e. 520 decisions in total). Decisions are marked as 'correct' or 'incorrect' i.e. are binary. I believe that chi square analysis is the "go to" in these situations. I was wondering if there was a...
  14. M

    Chi-square or test of equal proportions?

    Hello First post on the forum. I'm currently studying for my ordinary certificate from the Royal Statistical Society and using the textbook "Introducing Statistics" by Upton and Cook. Dispite pouring over the textbook I'm still confused as to which test to use for the following situation...
  15. J

    Statistical analysis for Rubric Based Research

    There are 26 participants who have participated in my research. Each participant treated with a lab module (Hands on Robotics Session). Now each participant will be evaluated using a rubric on scale of Excellent, Good, Fair and Poor. For my research i want to evaluate the following questions...
  16. M

    AMOS Bootstrapping - Mean Chi Square/df?

    Hi, I am working on a project modelling a variety of psychological outcomes for AIDS-affected youth in South Africa. Inevitably, some of our variables are not normally distributed, so we have used the bootstrapping procedure available in AMOS to estimate paremeters in the model...
  17. Junes

    Comparing museum visitors numbers using non-parametric method

    Hi all, I'm supervising a student who is going to do her research on visitor numbers to a certain exhibition. The museum will be actively promoting this exhibition in the month to come. The museum wants to know whether this marketing campaign had an effect on visitor numbers. So, we...
  18. A

    Is a Chi Square an appropriate test for this situation?

    Hello : ) I've been struggling for a while with this now; any help will be very much appreciated. I'm working on a project, which in part looks at whether the same whales are seen together more often than would be expected by random chance. Looking through my text book I thought the Chi...
  19. K

    What are some statistical tests for the relationship between two variables?

    Hi, I posted previously, but I haven't got any response, I assume its more appropriate to post in this forum, that's why I'm posting again. How do I test the relationship between Govt. Spending on Police and the Number of robberies (annually) I have 51 data points. I've done Pearson's, I...
  20. S

    Categorical data goodness of fit question

    Hello, I am trying to fit a log linear model with proc genmod and when i include all interactions (3 variables) i get the following: Criterion DF Value Value/DF Deviance 0 0.0000 . Scaled Deviance 0...