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 proportions

I have a sample of 65 participants. 20 chose A. 18 chose B. 14 chose C and 13 chose D. What is the suitable test to determine if there is significant difference in the proportions?
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2 sided vs 1 sided test

I am asking this questions straight from "Data Analysis and Statistical Inference " course by Dr. Mine Çetinkaya-Rundel on coursera! Please right click on the image and one in a new tab to make it ...
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Detecting heterogeneity in groups

This is a mockup of a dataset I am currently working on: ...
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Difference test between 2 groups where both groups contain depended and independent observations

Is there a statistical test to check the difference between groups (for example a paired sample proportion test), but where some of the observations of the two groups are dependent and some of the ...
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63 views

Tree structured proportion of success : statistical significance?

I am exploring a tree structured as follows: A/ parent node = parent population, size N, with a proportion of success for an experiment (eg. p = nb success / N) B/ child nodes = sub populations for ...
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Finding a statistically different proportion

I have the following problem: given a proportion $p_1=\frac{X_1}{n}$, where $X_1$ is the number of succesful outcomes in $n$ tries ($X_1$ and $n$ are both > 100), I have to find the smallest ...
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Binomial proportion confidence interval

I have a sample and I've classified each member into 3 groups A,B,C. To get uncertainties on the percentages of these groups, I've been told I should use the wilson score interval. As someone who is ...
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Comparing proportions from the (somewhat) same sample

I’m looking for some help on testing whether there are statistical differences between proportions when the data is dependent. By dependent, I mean that all the data is from the same participants ...
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Test of significance of multiple proportions in two groups

I have a dataset of two genetically different cell types, "A" and "B", and each of them can have four different morphologies, let's say "spiky cell", "elongated cell", "round cell", "triangular cell". ...
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Proportional data with multiple responses

I am trying to analyze a data set in which the response variable is a proportion that can range from 0-1 (inclusive). This response was measured from the same individuals under four different ...
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Question about the frequency definition of probability

In the book, it is written that the relative frequency or the frequency ratio gradually tends to become more or less constant as N becomes larger and larger. It is also mentioned that this is an ...
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Why is it not OK to do a Pearson correlation on proportion data?

An online module I am studying states that one should never use Pearson correlation with proportion data. Why not? Or, if it is sometimes OK or always OK, why?
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What is quasibinomial?

I'm hoping someone can provide an intuitive overview of what quasibinomial is and what it does. I'm particularly interested in these points: How quasibinomial differs to the binomial distribution ...
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normal distribution mean [duplicate]

Each week, John drives to his mother's house. The amount of time required for the trip varies and is normally distributed. On about 16% of trips, it takes him more than 54 minutes to reach his ...
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exact test on proportion: confidence intervals vs p value [duplicate]

I have the following 2x2 table NO YES 9690 5 LOW 26354 39 HIGH I want to plot the proportions and ...
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1answer
44 views

Comparing proportions between two mega-groups

Say I sit in 2 different restaurants, Cheesecake Factory and Panda Express, that has nothing in common on their menu. I randomly order items from the menu and record how much sugar it has as well as ...
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Estimating a single proportion from a marginal or conditional model

I had a single sample of a binary outcomes (success / failure), and I wanted to estimate the population proportion with a point estimate and a confidence interval. The problem was that some subjects ...
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Why use a z test rather than a t test with proportional data?

When testing the difference between 2 proportions why do we use a z-test rather than a t-test? Further, is there a simple way to conduct an omnibus test for significant differences between more ...
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45 views

CIs for proportions in Stata: ci vs. proportion command

I'm performing some basic analysis on a large data set (n-size after restrictions about 4,000) to supplement some qualitative historical research. The goal is to produce a variety of confidence ...
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74 views

Determine if two proportions from the same sample are different

Is there a test I can use to compare two proportions from the same sample that are not mutually exclusive? For example, I would like see if the proportion of people that answered "yes" to a ...
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Test for one category

I am doing a research in linguistics and I am not to sure what test to choose in the following problem. There is a group of 26 students. They are asked a question and two possible variants are ...
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53 views

How to replicate Stata's robust glm for proportion data in R?

There is an example on how to run a GLM for proportion data in Stata here: http://www.ats.ucla.edu/stat/stata/faq/proportion.htm The IV is the proportion of students receiving free or reduced priced ...
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GLM for proportion data in r

I have proportion data on the percentage of female employees in 500 organizations. I want to use GLM to explain this dependent variable using other independent variables such as company size, ...
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31 views

What is the problem encountered for confidence interval for single proportion when $n$ is small and $p$ is close 0 or 1?

My textbook says the $100(1-\alpha)\%$ confidence interval for $p$ has the form: It also mentions that this only works for when $n$ is large and $p$ is not too close to 0 or 1. It tried to ...
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Analysing grade distributions: difference in proportions across years

I have data on grades obtained in a course over three consecutive years. The grade distribution includes the number of students who received a fail, pass, credit, distinction and high distinction. I ...
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I'm stuck: How to 'bin' multiple binary outcome variables and then analyze within subject?

I have what feels like it should be a very easy analysis to work out, but I've been trying for hours and I can't figure it out. I'm using SPSS by the way. I have 10 (5 of each group) different binary ...
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49 views

What are the important conditions in ANOVA fixed effects?

I am working with an ANOVA model. I want to run a fixed effects ANOVA in which I have a ratio dependent variable and three independent variables with two and three levels. Obviously, before analyzing ...
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Comparing sample proportion to population proportion

I have a data set consisting of a number of different hospitals. I am trying to compare the proportion for hospital X to the overall proportion in the data set (which includes hospital X). Should ...
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31 views

chisq.test & post-hoc analysis?

I'm working on a R data frame, such as: - column 1 : ID - column 2 : count of event 1 - column 3 : count of event 2 (1 unique ID per row) I try to compare ...
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111 views

Clopper-Pearson for non mathematicians

I was wondering if anyone can explain to me the intuition beyond the Clopper-Pearson CI for proportions. As far as I know, every CI includes a variance in it. However, for proportions, even if my ...
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Mark and recapture with known upper bound

I was thinking this may be similar to a Mark and recapture problem where there is a known upper bound, hence the title. I am doing a proportion but sometimes the estimate is larger than the known ...
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Help with finding proportion [duplicate]

serve speed of a particular player was 102 miles per hour (mph)and the standard deviation of the serve speeds was 13 mph. Assume that the statistician also gave us the information that the ...
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26 views

Testing for differences in vegetation cover

I'm working on an analysis of vegetation where the idea is to compare the percent cover of different plant types (e.g., oaks) between two ecosystems. The way I measured percent cover was to do a line ...
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21 views

A model for multiple nested proportions?

I think this is more of a stats advice than code question so I've posted here rather than SO. My data looks like this (~300 more sample rows). ...
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24 views

Appropriate test for proportion data

I have two independent groups A and B. Each participant is given 5 questions to solve and his/her answer is evaluated as correct or incorrect. However, participants can skip questions, so the number ...
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76 views

One-way ANOVA appropriate?

I am assessing the performance of a hospital ward over 6 years. There have been two sets of changes to the ward over this time: after year 2 and after year 4. I have collected data in 4 sample ...
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Comparing two groups with many zeros

I am comparing the difference in time-activity-budgets of two populations of seabirds, those in the presence of ship disturbance and those not in the presence of ship disturbance. Focal animals were ...
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How to compare multiple proportions between multiple groups

I measured prey capturing success (=proportion of successful captures divided by the total number of prey captured) in four fish species (species 1: n=19, species 2: n=18, species 3: n=4, species 4: ...
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39 views

Binomial Response Difference Between Samples

I have a data set of 500 companies which have been clustered into groups based on their answers to survey questions. I'm trying to gauge whether the profitability between groups is statistically ...
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53 views

Statistical test for testing equal proportions

I have a questionnaire item (N=6572) for which: 5064 (77.1%) subjects responded to the question, and 1508 (22.9%) subjects did not respond to the question. What statistical test should i use to ...
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Proportion as Dependent Variable or Control for the Denominator in Regression Model

I am a little confused as to which model specifications to use for my question. I have number of technological failures (positive count variable) as dependent variable but I am supposed to control ...
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58 views

Validity of proportion estimate from finite sample

If I have a batch of 130 parts and I inspect a random sample of 14 parts, either accept or reject the part, and calculate the percent defective in the sample, how confident can I be that the percent ...
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37 views

Randomized Response, calculating probability

I have a problem with randomized response method when calculating the probability of critical attribute. For any of you who are not familiar with the method, you can check it here, Wikipedia Entry for ...
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37 views

Interpreting the result of 2-sample test for equality of proportions with continuity correction

I've done 2-sample test for equality of proportions with continuity correction. (This is the second course of statistic I'm studying so I know basically nothing, at least so it feels.) I'm using ...
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Simultaneous Z-test for the equality of two proportions (binomial distribution)

Is there a simultaneous test for the equality of two proportions when $k$ binomial properties are being tested? Example: Two groups of large size $n_1$ and $n_2$ are asked if they agree or disagree ...
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The $z$-test vs the $\chi^2$-test for comparing the odds of catching a cold in 2 groups

I just read in a rather well-respected (popular) science magazine (the German PM, 02/2013, p.36) about an interesting experiment (without a source, unfortunately). It caught my attention because ...
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70 views

Prevalence conversion to effect size in meta-analysis

I'm used to thinking about meta-analyses in terms of evaluating the impact of an IV on an outcome of interest (ex: relationship between a teacher's level of self-confidence and student outcomes), and ...
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p-values different for binomial test vs. proportions test. Which to report?

The following binomial test (exact binomial test) has a p-value of 0.05698, greater than 0.05 by a bit. 95% CI is (0.5698, 0.8077). ...
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95 views

Sample size calculation for a single proportion Without Any Comparisons (descriptive only): How to determine the margin of error in the formula?

I want to calculate the sample size for a single proportion (the prevalence of a disease). I know the formula and all: n = (z/m)^2 * P(1-P), where z is 1.96 (for 95% confidence level) and P stands for ...
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Frequency based discounting of values

Let's say there are two products A and B both of which have some value. Consider a population of ...