# Questions tagged [chi-squared-test]

A test (typically of distribution, independence, or goodness of fit), for the family of distributions use [chi-squared-distribution].

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### Frequency and hypothesis

which does it means? the results were processed using frequency tables of data obtained and expected data with a confidence level of 90% and with 4 degrees of freedom. To test the hypotheses, the chi-...
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### Power / sample size estimation for chi-square test with continuity correction in R

1._Some authors mention that they estimate sample size for chi-square test with continuity correction. For instance: Sample-size calculation is based on Pearson's Chi-square test with a two-sided ...
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### Chi square for three categorical variables

Can I use chi square test with three variables ? The variables are organizational climate (11 dimensions), job satisfaction (7 dimensions) and customer satisfaction (5 dimensions). Likert scale. any ...
1 vote
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### Why does the fact that I estimated my parameters change the way I should use chi−sqaured test?

Suppose I have a data sample and I want to test whether normal distribution with mean $0$ and variance $1$ fits this data sample. If I understand the chi-squared test correctly, I think that I should ...
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### When is it appropriate to rescale probabilities when doing a Chi-Square Goodness of Fit Test?

Suppose I have a vector of independent but non-mutually exclusive probabilities (e.g. both x and y can occur at the same time). ...
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### How to calculate the statistical significance of the difference in a categorical value of two populations?

There has recently been a statistical report regarding whether Cypriots are ready for a female president. There was a difference in the opinions of men and women and I'm wondering if it is ...
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### Sample size study not reflecting findings in R simulation

I have a binomial response variable (a sort of conversion rate for a search mechanism) and just one independent variable, which is the "type" of the search bar template. To illustrate, my ...
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### How do I combine two groups into one for Fisher's Exact test?

I'm fairly new to statistics and I need some help. I just ran a survey on colour terms in different languages. I had 3 groups with an unequal number of participants in each: English (27), Scottish ...
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### Validating random variable generation from inverse transform sampling

I'm building a simulator and I have to implement some probability distributions. What is the best (formal) way of validating this implementation? I took a look at KS-tests but it seems to me they are ...
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### Can the chi-square statistic in Kruskal-Wallis test be compared to determine the most appropriate to distinguish the groups?

I have a dataframe in R which format is similar as follows: v1 v2 v3 group 1 3.5 100 a 3 5 200 a 10 5.5 150 b 8 7.5 210 b 4 4.5 300 c 9 2.5 200 c ... My ...
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### How to interpret pvalue for Chi² goodness-of-fit test for Poisson distribution

I'm a bit confused about the pvalues I'd get when checking my own data against a theoretical Poisson distribution. Following e.g. this post here: https://stats.stackexchange.com/a/78175/66544 I'd ...
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### References: t-test and Chi-squared test can be conducted with unequal sample sizes

I have two independent groups: sample size of group 1 is 24000, and sample size of group 2 is 246. With the drastically different sample sizes in the two group, I need to use the Student’s t-test or ...
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### How to correct Chi-square's p-value when working with very unbalanced contingency tables?

I'm studying the association between a rare disease and smoking. Because the disease is rare, my contingency table is highly unbalanced with way more Non-Diseased than Diseased individuals, ...
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1 vote
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### Chi-squared approximation may be incorrect

Please I need your help. I am trying to run this data using R but it throws an error message 'Chi-squared approximation may be incorrect.' Is something wrong with my data? ...
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### Chi square fit, fitting data to a straight line: Incomplete gamma function as goodness-of-fit estimation

On page 661 of the book "Numerical Recipes in C:The art of scientific computing", we fit a set of N data points $(x_{i}, y_i)$ to a straight line model $$y(x)=a+bx.$$ We do this by ...
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### Confused about interpretation and intuition behind Mcnemar's Test [duplicate]

I've always been under the impression that Mcnemar's Test is for paired categorical data, just like paired t-tests are for paired continuous data. However, I was looking at the Wikipedia article for ...
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### How are effect sizes calculated following a cellwise residual analysis?

I have used SPSS to create a 2X4 contingency table concerning the relationship between two categorical variables: depression diagnosis and 4 sleep disruptions. I carried out a chi square test of ...
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### I'm not sure how to look at two frequency counts, measured each year for three different years

A friend has asked me to help them analyse some data. They have the following table of data: The table shows the total data for each year in a single hospital, not a sample. The final row is year to ...
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### Why is the chi-squared test statistic the accepted measure of distance for goodness-of-fit tests?

I understand the chi-squared test statistic to be a measure of "distance" from the expected distribution. So, for example, suppose I have a 3-sided (fair) die with sides x1, x2, x3. I roll ...
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### Reproduce chi-square p-value via simulation

I have a 3-sided (fair) die with sides x1, x2, x3. I roll the die 3000 times and tally the results: x1 * 990, x2 * 1050, x3 * 960. A quick chi-square test reveals that the probability of getting this ...
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### what formula does python statsmodels library uses to compute the bp_stat value (the Q value for the Box Pierce test)

As far as I know, the $Q$ statistics is computed with the formula $Q = N \sum_{j=1}^K \rho_j^2$ I created an example where I compute $Q$ by hand and by using:\ ...
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### Identify outliers in chi-squared goodness of fit test

I am performing a chi-square goodness of fit test to compare an observed value with an expected value. The expected value is calculated from theory. p-value suggests statistical significance. How do I ...
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