chi square

  1. T

    Choosing a statistical test when study includes both continuous and categorical variables

    Can logistic and linear regression be used when there are both continuous and categorical predictors? Is there any benefit to starting with ANOVA/t-test/chi-square?
  2. P

    Derivation of random variable for chi-square distribution.

    Hello all, In the chi-square distribution, how is the value of random variable derived. In the textbooks, the random variable is given directly as. 1st equation is for random variable, 2nd value is the test statistic used during inference of variance of a population. Source: Introduction to...
  3. M

    Should I use some sort of Chi Square Distribution or another method... Any assistance is greatly appreciated.

    I am asking for assistance or guidance to point me in the right direction for this problem I am trying to find a solution. Problem: I need to come up with a percentage to show a Severity of Defects for monthly software releases at my company. Each month our customers inform us of bugs/issues...
  4. M

    Chi Square & Weighted Average

    I am asking for assistance or guidance to point me in the right direction for this problem I am trying to find a solution. Problem: I need to come up with a percentage to show a Severity of Defects for monthly software releases at my company. Each month our customers inform us of bugs/issues...
  5. N

    Deriving Chi-Square for contingency table 2x2

    Hi Given a 2x2 contingency table, with a b c d as the observed values and n as the total, I have to show from the fact that Chi-Square = Sum(((O-E)^2)/E) Where E is the expected value of the observed, that: Chi-Square= (n(ad-bc)^2)/(a+b)(a+c)(b+d)(c+d). I just cant seem to get there. Any links...
  6. P

    Calculating representative value for data

    Assume there are ten data with values a_1, a_2, ..., a_10 each with different non-symmetric errors. The problem confronting me in brief is, to combine the 10 results a_i and their associated non-symmetric errors according to some acceptable precept so as to determine the value of a and its...
  7. A

    Chi Square or T Tests for Likert Scale Type Survey

    So I have a 4 point likert-type scale with approximately 20 questions. I have categorized each item to be either agree or disagree. I mainly did this because the previous person who used this scale did this. However, that person only displayed frequency data for it and did not run any tests for...
  8. W

    Comparing habitat use across seasons - what test can I run

    Hi, I've got some data on deer habitat use across 4 seasons and 6 different habitat types. I would like to test whether habitat use differs between the seasons but I can't work out what stats test would be suitable. Is anyone able to help me out? Also - I am unsure whether to use the raw...
  9. S

    Selecting of statistical test?

    I have a study whereby I asked two groups of participants (Clients (N=76) and Professionals (N=62) what qualities would make a treatment interaction positive and what qualities would make a treatment interaction negative. As part of my analysis I have totalled: - the number of positive...
  10. E

    Which test to use for three categories of frequency data?

    I have three categories of data (no change, uplisted, down listed). For each category I have a value for the frequency of occurrence. How do I compare these frequencies? It is essentially a one-way ANOVA type analysis that I want to do, but since the data are frequencies not means this test...
  11. A

    help needed with Fishers Exact Test (power calculation)

    Hello everyone. Hope someone can help me. I am running a Fisher exact 4 X 2 table analysis in SPSS. I have been informed its the correct test to use for the data. The problem is I have to conduct a power analysis to determine how many in both groups i need to be able to detect significance...
  12. P

    Difference between expected spending and observed spending. What kind of statistical

    I would like some advice from you about what kind of statistical analysis I could do about that data. My case is as follows: According to a research I have the information that the financial health of the company for a specific type of activity should put the following percentages on...
  13. K

    Anova or Chi Square for checking significant related effects

    Hi, I am a newbie to Data Analysis and would be thankful if you could explain to me if for this exercise I use Chi Square or Regression ( looking at the ANOVA table). For each what would be the specific steps? For example for Regression which is the dependent variable, etc. Exercise...
  14. E

    Am I understanding/describing this right? (chi sq, confidence intervals, ACE model)

    The experiment is a twin study - using pairs of twins to investigate similarities and differences and look at how much genes and environment contribute to an outcome. The purpose of the study was to investigate the contribution of genetics, to attachment disorder. It was also to investigate...
  15. J

    Goodness-of-fit test

    I have a question regarding goodness-of-fit tests. A general rule of thumb with the chi-square test of goodness of fit is that (1) no more than 20% of your expected frequencies can be less than five, and (2) none of your expected frequencies can be less than one. However, I am dealing with a...
  16. M

    Which test to use for these variables and their associations

    Hey, I have some questions about which test I can or have to use. Which test do I use to only identify if there is a relationship between those variables? I only want that to know, for the identification of confounding factors. Ordinal dependent categorical variable <-> ordinal...
  17. M

    Association between categorical and numerical variables using R

    Hi, I am new to this forum so please be kind :-). Not sure if this belongs in 'R'. I will describe my problem as good as I can. First of all I am using R commander for my Master Thesis. My Thesis is to identify if there is an association between one predicting variable (categorical 'less...
  18. S

    1 X 2 Chi Square? With controlled expected values?

    Good Morning, I’m wondering if you could possibly help me with a little problem. I have some data: 1. Number and date of disease outbreak each year 2. Date a warning system for this disease occurred each year based on environmental factors. I would like to get a p value...
  19. J

    Comparing data sets with two very different samples sizes - stats newbie

    Hi, I realize this question might have been asked before, or is very rudimentary, but I'm having trouble figuring it out. I have several data sets (~50) comparing outputs from two different brands of product from different areas of the country. The issue I'm coming across is that for Brand A I...
  20. J

    Contingency Table Analysis by chi square problem

    I am trying to figure out a chi square problem, and I keep getting stuck. The problem reads: A researcher tested single mosquitoes from five different locations for the presence of a particular virus and obtained the following data: Location A B C D E w/ virus 3 7...