Questions tagged [proportion]
A proportion is the fraction of some total that is of a particular kind, either (i) as a count of one type of thing out of a total count, or (ii) as a component of a continuous variable.
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Comparing Test and Control Lift in Proportion
I have two groups - a test/treated and control group - for which I am trying to assess whether the lift or percent change in proportion from a pre to post period between the two groups are unequal.
I'...
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Comparing survival rates
The question I have is focused on comparing remission rates at a fixed point in time.
For example, I have cancer type A and cancer type B (the two are not mutually exclusive groups) and all patients ...
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1answer
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Where is my potential flaw in my Z-test of Proportions?
I was working through this z-test of proportions example I found online. The online example solutions says that the difference between the groups is statistically significant, whereas I concluded it ...
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34 views
Is lmer or glmer appropriate for nested continuous proportion data
I have a reviewer that wants me to analyze my data along the lines:
Con_Ratio ~ Range * Latitude * Longitude + (1 | Genotype/Pair).
But I'm not sure if this can be done and how. My experimental ...
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33 views
specific equation for modified wilson confidence interval
I recently read the Brown, Cai, Dasgupta paper on interval estimation for a binomial proportion where they propose the modified wilson method as a better alternative to the standard wald interval. I ...
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1answer
24 views
Are there statistical tests for testing multiple sample proportion?
For categorical variable testing, we have chi-square test. For example, we want to test if a dice is fair (assuming sample has [6,5,7,7,6,5] and ...
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1answer
34 views
What statistics test to compare the repartition of multiple choices between two groups?
I made an experiment about UX where the participant has to detect among five differents configurations the one that he prefers.
The configurations are slightly different and are presented randomly 3 ...
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Why don't we need to use a t-distribution for difference of proportions tests? [duplicate]
In difference of proportions tests we use a Z-distribution. And in Chi square tests which I understand are in practice the same test use the square of the Z-distribution, the Chi square distribution ...
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compare distribution a categorical variable between a population and a subpopulation
So I have the following situation of having a population P with individuals belonging to categorical variable A, ..., N. From this known population I created several sub-population P1, P2 (each time ...
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1answer
28 views
Standard error of a proportion on a 2 x 2 contingency table
Why on a 2 x 2 table such as
where $p = \frac{a}{a+b}$
the standard error of $p$ is
$$\left(\frac{(a+c)(b+d)}{(a+b+c+d)^2(a+b)
}\right)^{1/2}$$
?
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33 views
Should I use a binomial glm, beta regression, uniform continuous distribution or nls with logistic regression for probabilities?
I made an individual based model in which there is a population of three types of individuals (lizards) that disperse randomly until they encounter another individual that has a beneficial effect on ...
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Comparing proportions between multiple groups - Fisher's exact test
I have a simple dataset on reproductive success of a certain plant species. Reproductive success was defined as a proportion between number of flowers and number of fruits. We measured on 10 different ...
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Cochran's Q test with changing proportions
for my thesis I am investigating the change in proportions of children in regular and special education. The information is obtained through an online questionnaire, and I have data for 4 consecutive ...
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29 views
Statistical test for binned proportion data in JMP / MATLAB
I have been trying to determine the proper statistical test for comparing binned proportional data between groups. My data set is individual subjects (4-5 per group) with 76-165 cells per individual. ...
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1answer
25 views
Z-score for weighted proportion
I have a question regarding the Z-Score test when it comes to compare two proportions.
Usually, one would use this formula to obtain the Z-Score:
and then compare it to a Standard Normal ...
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22 views
Testing the goodness-of-fit for the binomial distribution
As specified in the title, I'm trying to understand how to test the goodness-of-fit for the binomial distribution; to this aim, I followed what suggested in this link.
Particularly, I'm investigating ...
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16 views
How do I model whether compositional data changes over time? [duplicate]
I have a data set of diet proportions over time (this is just a sample):
...
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15 views
Compare overall proportions between 2 samples
I want to compare multiple proportions between two samples. There are 60 brands of toys (T1, T2, T3...T60). I would like to know if overall, the proportion of respondents who own each brand of toy is ...
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probability to belong to the majority class based on observed proportions
I have a population of several categories and I don't know the proportion of these categories in my population. I want to draw (with replacement) in my population until I can say with 99% certainty ...
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1answer
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How to report percentage change in proportions?
I want to compare changes in the proportion of fruit purchases over time for a household. For example, in year 1, 4/40 (10%) fruit were apples, in year 2, 12/80 (15%) fruit were apples.
When ...
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2answers
32 views
How to define sampling unit. t.test vs proportion test
In my particular case I am comparing damaged fruit in several treatment fields vs. several control fields
For simplicity:
Both treatment and control have 10 bushes each. a cluster of fruit is taken ...
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0answers
12 views
hypothesis testing of proportions between two groups for survey data
I have a question regarding hypothesis testing of proportions in a survey.
The survey has 7,000 full responses and consists of 5 questions, each with 3 possible answers;disagree, don't know and ...
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2answers
300 views
Regression when both the predictor and outcome variables are proportions
I am using
$X$ The estimated pre-game win probability of a sporting team playing on its Home field (estimated according to a certain model)
to predict
$Y$ Actual proportion of points scored by ...
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0answers
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how to compute a minimal sample with some prior information?
Suppose N = 30, 000 students in total and a SRSWOR of size n will be taken from the population. And we want the proportion estimator ^p to achieve the precision with tolerance level e = 0.03, risk α = ...
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4answers
63 views
Frequencies/percentages different from zero - which test?
I conducted an experiment and had participants indicate binary judgments by either pressing "1" or "0" when seeing different types of stimuli. Now I want to test whether the proportions of number ...
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1answer
77 views
How likely is a random sample to be significantly similar to the full population?
I am looking for a way to compare the proportions between two data sets of surveys, where individuals can be placed in more than one classification.
One of my groups contains the survey results of 10....
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2answers
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Calculating sampling proportion's standard deviation given population proportion?
So the question is as follows (paraphrased):
A population votes for/against a political candidate. In a sample of 200 voters, let $X$ be the fraction of people who vote for this candidate.
...
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1answer
38 views
Interpretation of variable in a probit model
I am struggling interpreting the coefficient of a variable which is expressed as a proportion in a probit model. As it currently stands , I am interpreting the average partial effects of this variable ...
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0answers
41 views
Chi squared test: which is the correct null hypothesis?
I'm reviewing some literature in my field, specifically looking at whether physical activity (PA) has any beneficial effects on cognitive performance. The results across the studies are quite mixed. ...
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1answer
34 views
Bernoulli / binomial trials for a process with variable probability of success
One of the conditions for a Bernoulli trial (and by extension binomial proportion confidence intervals) is that the probability of success is the same every time the experiment is conducted.
In the ...
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1answer
29 views
Model proportions as independent variable for binary outcome
I've binary (disease) outcome: 0, 1 with certain independent variables in proportions, and other covariates as - age, sex.
There are Packages that model proportions as outcome variable but not other ...
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0answers
53 views
Beta regression where fractional response adds up to 100%?
I have a data set of people switching brands.
Say #people switching from Brand A to Brand B, C or D.
My data looks like this
...
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0answers
38 views
z-test of proportions vs chi-squared
A 2-sample z-test of proportions and a chi-squared test can both be used to analyze a $2\times 2$ contingency table. In fact, for $2\times 2$, $\chi^2=z^2$. Why can the same table, being used with two ...
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How to test for a reduction in gendered language? What would the outcome variable be?
Say I’m looking at dating website profiles. I note 20 adjective that are much more likely to be used on females’ profiles than males’ profiles. I note another 20 adjective that are much more likely to ...
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Variance of the average of two (or more) Net Promoter Scores?
As per Wikipedia,
"The Net Promoter Score is obtained by asking customers a single question on a 0 to 10 rating scale, where 10 is "extremely likely" and 0 is "not at all likely": "How likely is it ...
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1answer
24 views
One-Sample Test for differences between questionnaire-answers
For a rather large sample (>800 participants) I have answers from a questionnaire, containing multiple Yes/No-Questions.
What I want to find out is, if the proportions of yes & no's differ ...
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20 views
How to test for difference in weighted proportion difference? (and average weighted proportion differences)
Suppose I have a survey where respondents rate different questions as positive (1), negative (-1), or neutral (0), and their responses are given a different weight based on which job they have and ...
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Comparing complex proportions between groups
I have a set of data where cells were collected from a number of subjects and phenotypically categorized (sample data below). I'm interested in asking how sets of antigen-specific cells change in ...
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1answer
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Distribution of estimator of multiple (spatially related) proportions
Consider a spatial random process $Z(s)$, where $s$ denotes the spatial location.
Our objective is to delineate the zone $\mathcal{Z}$ where the probability that $Z$ exceed a given threshold $\zeta$ ...
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1answer
49 views
Confidence interval for raw number of correct binary predictions
Let's say there are 600 games in an NBA season, and a competition among individuals to correctly forecast the winners of the games. The forecasts are not expressed probabilistically but simply in ...
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2answers
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What is the best way to display confidence intervals around a proportion?
I was reviewing an article about the effectiveness of a vaccine and it expressed these in % effectiveness = 1 - odds ratio. So far, so good.
But they showed confidence intervals around the %'s, both ...
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0answers
38 views
Analyzing tritomous categorical variable between- and within-groups
I have data examining a decision task across age groups. For the decision task, responses are categorical and coded into 3 possible decision types (A, B, C) that are mutually exclusive and exhaustive ...
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22 views
Repeated measures and bootstrap
I have data from 100 individuals where:
100 got test 1
50 got test 1 and 2
The outcome is binary
I've just started statistics this summer, and was told to use a generalised mixed model to check for ...
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0answers
19 views
comparison of multiple groups when the dependent variable is a percentage
I am measuring the proportion of different types of bacteria killed by 4 different antibodies (simplified for illustration)
...
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0answers
9 views
Mantel Test of Proportion : Aggregating categories different significance
I have a dataset representing for a specific marketing event editions (1 event per 1 year), the number of partecipants, and the outcome of their partecipation
If In sas I use the Mantel Exact test to ...
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0answers
13 views
comparing multiple groups by frequency
I have three columns:
first one is the number of innovations by handicapped students,
the second column is the number of handicapped students in a class of a school, and
the third column is the total ...
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0answers
21 views
Longitudinal beta regression with random effects
I'm interested in modeling a proportion outcome (malaria positivity rate) as a function of some discrete and categorical variables.
The dependent variable was measured repeatedly over time (3 years).
...
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1answer
34 views
Type of studies reviewed in meta-analysis of proportion
What types of studies are reviewed for meta-analysis of proportions? For example can I included case-control studies and collect data of number of events from the total cases?
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How to model if a company is mentioned in a review (volume) and how it is mentioned (valence)?
I am working with social media data of Brand A and would like to model what features of posts of Brand A are linked to if a competitor (Brand B) is mentioned in the comments of different posts of ...
