The proportion tag has no wiki summary.
3
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1answer
53 views
Statistical tests when each variable in a sample is a percentage
I am performing a temperature preference test in mice. Mice are placed into a chamber with one half of a chamber having a cold floor and the other half having a warm floor. Mice spend a specific total ...
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0answers
42 views
Interpretation of the OLS regression coefficient of a proportion dependent and interaction independent variable with dummy
I have two regression models; I am not sure how to interpret the coefficients. In the first one the dependent variable is earnings management proxied by (abnormal accruals scaled by total assets), the ...
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52 views
Is there evidence to say with 99% confidence that the proportions are different?
A college placement service interviewed 1,100 graduates to determine if they were satisfied with the teaching they received. Of the 400 who had taken statistics, 225 said they were satisfied. Of the ...
3
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0answers
164 views
Ratios of means - statistical comparison test using Fieller's theorem?
I would really appreciate any suggestions with the following data analysis issue. Please read till the end as the problem at first may appear trivial, but after much researching, I assure you it is ...
3
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1answer
59 views
Are the posteriors “different”? How does one discuss the result?
First, I realize this may be a basic question. However, when I search the web for references on this issue, I run into the problem of wondering if the description I'm reading is applicable to the ...
3
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1answer
107 views
P value and confidence interval for two sample test of proportions disagree
I'm using R to calculate the two-sample test for equality of proportions, where the two proportions are 350/400 and 25/25. So:
...
1
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1answer
43 views
Multivariate regression and use of proportion type variables as DV in it
I have two very important things to know. Can anyone help?
Question-1
If I have three categorical dependent variables and a continuous dependent variable, which are correlated (or associated), then ...
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29 views
How to compare multiple groups which are binary?
I have a dataset on 4 websites where I have asked whether a respondent is happy or not about each of the 4 websites.
Website1, Website2, Website3, and Website4 are column headings.
With data as ...
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0answers
29 views
Is chi-square enough to prove relationship or there is need to test for proportions?
If I test for chi-square and found a p-value <0.05, and I and can see from data that 80% of males exercise, is that enough to prove the relationship of I need to use proportions test ?
Thanks !
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0answers
112 views
Formula for calculating sample size for comparison of two proportions
The formula for calculating sample size in a two sided hypothesis on two proportions is:
$$n_1\ge \frac{\left(Z_{1-\frac{\alpha}{2}}\cdot\frac{S_0}{S_1}+Z_{1-\beta}\right)^2S_1^2}{(p_1-p_2)^2}$$
I'm ...
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0answers
25 views
Zero to one proportion data, with quadratic term?
I have a data set with the following:
N = 60;
x = developmental stage (range 25 to 44);
y = proportion of 10 minute trial performing a behavior (range 0 to 0.81; 30 zeros)
A scatterplot produces a ...
1
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3answers
216 views
Statistical test on percentage data with replicates
Imagine I am doing an experiment where I want to look at the cellular composition of tumour samples
I have 3 samples with phenotype A (e.g. metastasizing) and 3 samples with phenotype B (e.g. not ...
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0answers
80 views
What test of independence of sample proportions is appropriate when n is very large and p is very small?
I have the (not necessarily veridical) impression that typical textbook independence tests of proportions are intended for use the proportions involved are not super small.
In my case n may be 10^8 ...
3
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2answers
120 views
How does the confidence interval for the parameter p of a bernoulli trial vary with the value of p itself?
This is a very basic question (I'm currently studying undergrad level statistics), but I was hoping for some clarification regarding an assertion I read in a newspaper article earlier today. The ...
2
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1answer
169 views
is the z-test for difference of proportions valid for massive samples with tiny proportions?
Let's say I want to run a difference of proportions test where each side has n=23,000 but their proportions are 0.21% and 0.34%.
...
1
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1answer
44 views
A statistic to describe a correlation with progression
I want to see if the proportion of 'I don't know' responses correlates with the progression through the survey. Generally we expect this proportion to increase ...
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0answers
81 views
Which Statistical Test
I have a variable (VAR1 )with two possibilities, let's call them V and N.
I asked my experiment participants to detect the VAR1 value.
My aim is to compare the correctness rate of answers by ...
4
votes
1answer
75 views
Multivariate proportional data
I am looking for literature on what I call multivariate proportional data where a single observation is a vector of proportions that sum to 1. For example, each person weights their preferences for ...
1
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2answers
269 views
How to test (in STATA) whether the gender distribution of employees to jobs differs across two companies?
I have data on several companies where some are headed by a male CEO while others by a female CEO. As you can imagine, the jobs within these companies have different gender compositions. What I am ...
2
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1answer
90 views
Can we use as predictor a variable that was used in the calculation of the dependent (a ratio)?
I wonder if someone could give me some advice on the problem of using ratios as a dependent variable in a Generalized Linear Model.
I'm having the following problem:
I have a variable referring to ...
3
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0answers
82 views
Appropriate statistics for proportions where categories are composites of independent binary variables?
I have data in the form of three digit binary numbers (i.e. 100, 101, etc.) scored for each individual in my samples taken from two populations I wish to compare. The three numbers represent ...
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0answers
51 views
Estimating population size and a proportion
I am interested in the following sampling problem, which I will try to describe by a motivating example.
Suppose we want to estimate how many people in a certain area, has blue eyes, how many have ...
0
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1answer
77 views
How to regress a time series of proportions?
Every month, an organization surveys some of its customers (the total number of customers is also known).
The sampled customers answer a survey with a dozen or so questions; sometimes, customers ...
2
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0answers
83 views
How to test if two coins have different biases?
probably a noob question because I'm a noob.
I have two coins, A and B. For each coin I have a sample of the results I get by tossing it. My null hypothesis is that A has equal or higher probability ...
5
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1answer
122 views
What is the standard error for the distribution of the difference in proportions (for hypothesis testing)?
I am looking for the standard error for the distribution of the difference in proportions for hypothesis testing when the null hypothesis is that the two proportions are different by a constant.
...
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0answers
44 views
Replication in multivariate logit in R
I am new to both logit models and GLMs, but I think one of those two model classes might be the correct analysis for my data set:
I am interested in comparing the composition of the diet of fish ...
4
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2answers
104 views
Smoothing a time series of ratios
I have a time series of proportions, $x_t = \frac{a_t}{b_t}$ i.e.
$x_1 = 2 / 30, x_2 = 1/10$, ...
I want to smooth $x_t$. Should I apply a smoothing function directly to $x_t$, or should I smooth ...
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0answers
192 views
Simultaneous confidence intervals for multinomial proportions: pooling replicates or not?
I observed 21 times a response that could be one out of 8 categories (multinomial response). I computed the proportions for each category.
I did it independently 12 times. Hence I have 12 replicates ...
0
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1answer
116 views
Likelihood function to compare two binomial variables
I'm starting studying maximum likelihood estimation, and I have came across to a problem that I don't know how to solve yet.
How can I write the likelihood function to test the hypothesis that some ...
1
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1answer
150 views
How to calculate proportions for two sample t-test from data frame in R
I'd be very grateful for any help you can provide with this question - I've been using R for survival analysis, which has led on to a study looking at CMV reactivation - I initially started using time ...
3
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2answers
692 views
How are confidence intervals for proportions computed under SPSS?
I wonder whether any of you can help me. SPSS puts confidence intervals in graphs of frequencies and proportions,
but it clearly is not using a normal approximation, i.e. it is not using the formula ...
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0answers
26 views
Hotelling for testing proportions
I have two groups with N individuals each. For each individual, three parameters are measured, which always add up to 100%. I want to test whether the groups are different.
Would Hotelling's ...
0
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2answers
559 views
How to test for equality of means for proportions? And two-sided or one-sided?
I have the following problem: two groups A and B.
The proportions of married and single are ($p_1$) and ($p_2$) respectively, and the standard deviations ($s_1$) and ($s_2$). The sample consists of ...
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1answer
57 views
statistics on proportion wise data
What are the usual statistical procedures used for data that is in proportions ? I have data about survival proportions of two species across 7 elevations .. What statistical tests could I run apart ...
2
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1answer
208 views
Test for multinomial distribution
I have a sample of animals and a categorical variable of $L$ behaviors $i=1,...L$. I computed the proportions of this sample corresponding to each behavior category $p_{i}$, $\sum p_{i}=1$.
Can I ...
3
votes
1answer
130 views
Which statistical test to test if counts from different populations are actually different? t-test versus chi-squared
I'm having a hard to deciding which of a two-sample t-test and a chi-squared test is more appropriate for these sorts of questions. Examples would be:
70 out of 120 americans like hotdogs. 50 out of ...
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72 views
Formulating hypothesis and choosing the appropriate test when dealing with proportions [closed]
Monoamine inhibitors are highly effective in treating patients who suffer from panic attacks, providing relief to 80% of individuals who take them. Investigators believe that monoamine inhibitors used ...
3
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2answers
400 views
Comparing proportions across more than 2 groups
I'm a clinical researcher and I am comparing children who had fluid in the abdomen (ascites due to liver disease). I have 4 groups based on the kind of fluid analysis and in each group I have ...
1
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1answer
45 views
If my counts are from a proportion (resampling) of a sample, does it influence the confidence interval?
The aim is to estimate the proportion (or counts) of a certain species among a collected sample. Due to the large number, it is not possible to count through the whole sample. So I have to select a ...
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66 views
How to compute the confidence interval if I have 2 samples?
In the field of biology we often have >1 samples. For instance I can conduct two (but not many) experiments (replicates) each on a number of animals (n1, n2). The aim of the experiment is to estimate ...
1
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1answer
123 views
Nonparametric chi-square test
I have two independent populations (up and down), each population contains three categories 1,0,-1.
For example:
...
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2answers
487 views
Safely determining sample size for A/B testing
I am a software engineer looking to build an A/B testing tool. I don't have a solid stats background but have been doing quite a bit of reading over the last few days.
I am following the methodology ...
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0answers
186 views
Panel regression with proportion as both dependent and independent
I need to do a panel regression where my data is proportions for both dependent and one of the independent variables.
I do not have the underlying data for the proportion so I cannot expand the data ...
0
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1answer
250 views
How to interpret the odds ratio in a logistic regression with proportion as a response variable
I have a glm model for some data with a proportion as the outcome variable as follows:
...
6
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2answers
293 views
How do I reject or fail to reject the null hypothesis that p1 = p2 = p3 = p4?
I need to do reliability analysis on computerized test questions. Given a multiple choice question, if 20/25 got it right the first time the test was given, 22/30 the second time the test was given, ...
0
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1answer
105 views
How can I calculate the confidence interval for the mean of sample proportions?
I have a process that generates a sequence of events, where each event is of a certain type (let's say $A$, $B$, and $C$). The length of each generated sequence is random.
I wish to count the number ...
2
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2answers
72 views
Difference in proportions but one of them is 0
What is the best way to test for difference of proportions when of them is 0% (or 100%) ?
edit: I have two raters, who give a score of either 1 or 0. One of them gave a 0 in every single case. Now I ...
4
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2answers
483 views
Chi-squared and repeated measures
I would like to determine whether there is a deviation in the male:female ratio of a certain strain of laboratory mouse from the normal situation (with male:female = 1:1).
I have several mouse pairs, ...
2
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1answer
412 views
How to test a difference in proportions for significance when the underlying distributions are not normal?
I have a list of categories A, B, C, etc, each with a probability:
A .015
B .005
C .02
D ... etc.
I need to find if the difference between two of these ...
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0answers
175 views
Two Sample Proportion Test - Finite Population
If there is a population that we consider fixed (finite) with size N - say the customers at a bank at the end of a given month - and we want to conduct an experiment on this population by randomly ...
