# chi square test

1. ### Simple Random Sample vs. Population?

I'm a little confused about whether or not I need to use a simple random sample in a problem. In order to justify his style of teaching, Professor X is trying to evaluate whether or not students who take his Math 101 course are more likely to continue to the next semester than students who...
2. ### Categorical variables in SPSS - Chi-square and then what?

Good morning from Portugal! I´m a biologist and I use SPSS for my statistical analysis. I have some categorical data from questionnaires and made a chi-square analysis (most of the data had assumptions violated, so I used Fisher´s Exact test instead) followed by Phi or Cramer´s V to analyse the...
3. ### Statistical significance/ probability

I have data for number of different vehicle types (cars, 2-Wheelers, 3-Ws, other) and which vehicle is following (going behind) which vehicle in 5 lanes (one direction). For example, In this table, 3Ws are following 120 2Ws and 90 cars. In other table it shows total number of vehicles present...
4. ### How to study the effects of alcohol consumption on happiness & cognitive function?

Hello, I want to study if there's a relationship between alcohol consumption and happiness + cognitive function. Most of my data is nominal or ordinal. To measure alcohol consumption: How often respondent has had an alcoholic drink during the last 12 months To measure happiness: Overall...
5. ### Count data and exposure

Hi, I have seven categories, 'monday','tuesday','wednesday'... Each category contains count data, however I have a different number of observations on each day - some days have 10 observations, some 12, some 21. I want to test to see if the day of the week has an influence on the count and...
6. ### What alpha spending formula to use for chi square test of independence ?

Hi all, For a website CRO (conversion rate optimization) trajectory project of a client, I’m trying to setup a way that they can sequentially check whether an A/B test ‘reached’ significant results (i.e. Does website B lead to more transactions, than website A?). Much like clinical trials, data...
7. ### Determining how similar different sets of data are

I hope this is in the right spot: I have a dataset of ~15,000 unique, nominal, categorical members. From that dataset, I have ~3,000 samples that are subsets of the overall dataset. Each sample has 100 unique members. A member's inclusion in a sample/subset is binary: either it is fully...
8. ### how to draw contingency table for repeated experiments(multiple samples)

the aim is to decide whether gene types can affect response to certain stimulus. there are 3 types of genes(G1-3), 3 kinds of responses(R1-3). in one experiment, dozens individuals from each gene group are involved, some of them (a) showed response 1, some showed R2, etc. so the contingency...
9. ### Can I use chi-square for one nominal and one ordinal variable?

Can I use chi-square test of independence if one variable is nominal and the other is ordinal, or do both have to be nominal?
10. ### Chi Square test

Hi Guys, Hope you all are doing well. I am very new to statistics and I have a little doubt regarding what test to use to analyze my data. I have some bacterial population counts (4 bacterial species) for 4 different geographical sites. I wish to see the association between bacterial prevalence...
11. ### Calculating ensemble value for data with non-gaussian errors

I have 10 data points each of which have non-symmetric (i.e., non-Gaussian) errors. That is, if 'a' is the central value (representing the median), then a^{+b}_{-c} means that 'b' is the positive 1-sigma error and 'c' is the negative 1-sigma error. I want to be able to get a representative value...
12. ### comparing two sets of data

hi, i want to check whether the two samples can be drawn from the same distribution. can i do it with chi-square test? what are the assumptions i need for it? if i can't use chi square test - what can i do? notes about the data sets: - discrete - mostly increasing (in particular - not...
13. ### Randomness testing using frequency within a block method, chi-square statistic doubt.

The chi-squared statistic under the frequency within a block method is defined as 4M summation of (proportion of 1s in block - 0.5 ) ^2 where M is the length Of each block I understand that this follows a chi-square goodness of fit test observed-expected frequency square. But where does this 4M...
14. ### How to apply Chi Squared test according to this Simulation?

Hi there, I have been wondering about some points of Chi squared test. I would like to introduce the following scenario to better clarify my question: Let's say that one day while doing research on the city of Villy God has appeared to me and told me that city there are 10,000 adults...
15. ### Interpretation of the Likelihood Ratio Chi-Square Test Statistic

Do I still use the Chi-Square distribution table to determine the significance of the Ratio Likelihood Chi-Square test statistic? I know you use it for the Pearson's Chi-square test statistic, so I am unsure whether to same rules apply. I calculated the Likelihood Ratio Chi-Square in SPSS...
16. ### What do I do when the chi-square assumption is violated

Hello, I am looking at data to see if there is a correlation between an Independent nominal variable (3 level) and a hypothesized dependent nominal variable (2 levels). SPSS shows a statistically significant chi square and Cramer's V, but an assumption is violated. The expected count is less...
17. ### Help!

I have a problem that is probably fairly simple but I have writers block. This is to do with unnamed animals. I have three tests I have conducted on different samples of animals. The possible outputs are simply alive/dead (please ignore the obvious moral implications). The tests are: Small...
18. ### Pearsons Correlation, Two-way ANOVA, Linear Regression Test, Chi-Square Test or None

During research, you have asked your participants whether or not they have ever experienced financial difficulties (yes or no). You have three age-groups (16-20; 21-25; 26-30), and you predict that those in the 26-30 group have a greater risk of experiencing financial difficulties than those who...
19. ### Comparing groups/sites---need advice identifying variables and appropriate tests

Hi, thank you for reading this and your potential input. This is a research study. I examined the prevalence of parasites in one insect species in an island ecosytem. Insects were collected from: Island 1: 3 sites (all very different elevations) Island 2: 2 sites (similar elevation)...
20. ### 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...