The population tag has no wiki summary.
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How to best account for population sizes in disease outbreaks
Say one has the the fatality and survivor rates of a pathogen in terms of geographical location (e.g., the latest data on the MERS-CoV).
...
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2answers
95 views
+200
Population model to model year to year dynamics
My task is to assess how various environmental variables affect annual population fluctuations. For this, I would use a model like:
$$
\mbox{log} ( \mu_{i,j+1} ) = \mbox{log} ( \mu_{i,j} ) + R_{j} + ...
4
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1answer
43 views
Population standard deviation for a binomial(?) distribution?
I have been confused by two separate questions (Stock & Watson - introduction to econometrics ch.3), using different values for standard errors.
The first: In a survey of 400 voters, 215 respond ...
3
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3answers
136 views
How should I color scheme a heat map based off data below?
I have subdivided the globe into 100 sq mile bins and then collected how many tweets were sent with a geolocation within each bin. At first I color coded each bin on the map based off a standardized ...
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0answers
26 views
Combining covariances
Imagine we have one sample (n=40) from a population on 2 variables, for which we estimate the covariance (say, 0.1). If we would have another sample (n=10) from the same population, and we estimate ...
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2answers
41 views
How do I give a larger weight to a smaller population?
I have a set of cities ranked 1-10 based on several criteria. I also have the percentage of the total population living in these cities. I want the cities with smaller populations to be able to ...
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0answers
27 views
Fisher's exact test for comparing 2 years of population data?
I am a young ecology graduate student who is starting to learn statistics. I've already collected some data on our study populations that my adviser has asked me to analyze.
There are 20+ populations ...
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3answers
104 views
Best method to analyse whole population data
I have data of an entire population (N=27). I would like to find out which variables (of many) have the greatest effect on one certain dependent variable, and how much of its variance can they ...
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2answers
180 views
are there any statistically significant differences between my study population and a sub-group within it?
I have a total population of 31, of these I have a treatment finishing population of 20.
I want to run a test on SPSS to identify if there are any significant differences between the 20 individuals ...
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1answer
57 views
Conditional fixed effects Poisson *with population exposure*
Reading a paper, the authors use a "Conditional fixed effects Poisson with population exposure." I wasn't sure what "population exposure" meant, so I looked it up. It seems like the term comes from ...
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2answers
112 views
Population Variance and Sample Variance
How is it that lowering the number of frequence,$n$ by $1$ in the for formula for Population and Sample Variance account for the discrepency of using sample rather than population.
I mean how is ...
2
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1answer
52 views
Good distribution for modelling age in a population
What is a good distribution for describing the age structure of a population? For example, if I want to know the probability that a member of a population is less than or equal to 20. How can I ...
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1answer
52 views
Mixing User Data For Cross-Validation
I have data from 12 users, and want to perform cross-validation. Is it necessary that I create my training and test data from different users, or can all of the data be randomized, and then split into ...
4
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1answer
63 views
Is a chisquare on a (nearly) complete population data necessary?
I have data from a survey that was (attempted to to be) administered to all children of particular grades in a certain state. I am getting it after a cleaning step by the survey designers that removed ...
1
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1answer
77 views
Sampling distribution of means
Im working through a textbook atm and Ive read that the mean of "the sampling distribution of means" is the same as the "populations" mean.
To construct the sampling distribution of means, i need to ...
1
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2answers
71 views
What does population actually refer to?
This is probably going to sound extremely stupid, but it's part of a larger question, about sample distribution of means, that I'm having problems understanding, so please bear with me.
If I record ...
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1answer
82 views
Population vs sample variance
This is perhaps a very basic question, but I am a bit confused. I have a time series of day some time varying data, say the amount of sunlight as the day passes.
I bucket the data in say 10 bins say ...
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0answers
83 views
What is the mode of US height, in inches? What percentage of americans does this mode represent?
I am setting the starting-height of a console, and so I would like to know what the most common height is, and what percentage of americans the console would not have to move for. I am shocked at how ...
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0answers
21 views
The statistical prevalence of solely negative genes in the adult human population?
I really hope I'm not asking this question on the wrong stackexchange site, but seen as this question has a lot to do with statistics I'm guessing I might be in the right place.
There are certain ...
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1answer
77 views
Identifying populations and samples from a dataset
I'm writing a proposal for a restrospective cohort study using registry data. Am I right to think of the registry data as the whole population?
If it is the population, then am I right in thinking ...
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0answers
22 views
Estimating the confidence interval for each half of a population
We are looking at how a change in the environment (confinement level) alters which of two behaviors our model organism chooses. We perform several trials at each confinement level. Each of these ...
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0answers
49 views
Sampling rate for Bayesian analysis of user survey with discrete random variable
I work on a website that gets around 150,000 unique visitors a month.
I am proposing to sample one in 1,000 people visiting the site with a pop-up survey as described in this question and answer ...
1
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1answer
93 views
What does “return rate” mean in population ecology models?
What does "return rate" (tasa de retorno in spanish) mean in population ecology models? In context of capture-mark-recapture models. I have found many articles on ...
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3answers
118 views
Confusion between sample and population
A team has conducted a study in which an introductory class was
randomly divided into two groups. Group 1 was administered a dosage of
alcohol. Group 2 was given an equvialent dosage of ...
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0answers
148 views
What is minimum sample size to get significant?
I want to test whether there are any significant differences between Public Relation Strategies of the companies listed in the Malaysia Stock Exchange.
The total population is 825 companies within 13 ...
1
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1answer
225 views
Comparing proportions from the same sample of patients
The question I have is how to test if two proportions from the same sample of patients are significantly different from each other, indicated by a p-value?
Example: 100 people, 1 has Disease A and 2 ...
2
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2answers
2k views
Deciding whether to use r^2 or adjusted r^2 (specific situation)
I read online that it is only necessary to use adjusted-$R^2$ when you are working with a sample rather than the entire population.
The data I'm working with is information on a series of live ...
3
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2answers
779 views
Difference between superpopulation and infinite population
What is the difference between Superpopulation and Infinite population? Please explain this with examples.
Thanks!
3
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2answers
1k views
Difference between a census and a sample
I know when you do a census, you cover the entire population but when you take a sample, you select a group from the population. There can be only one census but there can be many different samples ...
3
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3answers
651 views
Identifying the population and samples in a study
I apologise for the silliness of this question. I ran an e-learning experiment using a class of undergrads. Participation was voluntary, so only half of the class participated.
I know that my sample ...
2
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3answers
662 views
Significance test for non-normal population?
I'm a journalist, and I am trying to work out whether hospitals that are in political districts with low majorities (i.e. where the political representative is fighting hard for his or her seat) are ...
1
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0answers
113 views
What is the correct way of estimating the proportion of individuals in a population from a count of their individual parts?
My original question was going to be : How do you estimate the proportion of species in a population from count data of their individual body parts, provided that you can identify each part as ...
1
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2answers
88 views
What statistical measures are recommended for mixing of population samples?
I want to know what statistics should be used to measure the mixing of languages in cities in a country/state. I have samples from individuals and know the language they speak and the city they live ...
5
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1answer
61 views
Estimating species distribution and rate of expansion using only positive data
Short version: is there any statistical method that can be used to develop estimates of abundance, spatial distribution, and/or rate of spread of a species when my dataset only includes presence data ...
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2answers
933 views
Does transformation of r into Fisher z benefit a meta-analysis?
Usually r is transformed into Fisher z to test difference between two r values. But, when a meta-anlysis is to be performed, why we should take such a step ? Does it correct for measurement error or ...
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42 views
Determine weights from selection probabilities in a “with replacement” sampling scheme [duplicate]
Possible Duplicate:
Derive househould weights from a uniformly distributed person sample
EDIT: Essentially, I have answered the question myself in the linked question: Derive househould ...
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3answers
181 views
Calibrating a household survey to household-level and person-level control totals
Imagine a (reasonably large) household survey where all persons in every household have been questioned. For the purpose of microsimulation, this survey needs to be expanded to a full population. In a ...
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2answers
62 views
Inferring a likely full population from multinomial measurement or survey data
Assume that we have one or several multinomial samples (e.g., surveys) taken from our population. While inferring characteristics (such as mean values, correlation, ...) from a multinomial sample is a ...
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1answer
887 views
Testing for significance of difference between two populations
I am trying to test the significance of the difference between two populations.
Here is a link to the population 1 data: http://pastebin.com/914mCRqA
and population 2 data: ...
5
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2answers
178 views
Combining the results of two surveys
Someone has surveyed a number of people and put the results in a database (Survey 1). Each observation has additional information that, for any subpopulation (men only, young only, etc.), gives a ...
2
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1answer
122 views
In benchmark tests should I use formulas assuming a population or a sample?
I have a single JavaScript benchmark test that I run a number of times and store the results in an array.
I then calculate the mean, variance, and standard deviation of the results of the runs.
My ...
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5answers
7k views
What is the difference between N and N-1 in calculating population variance?
I did not get the why there are N and N-1 while calculating population variance. When we use ...
1
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1answer
50 views
Is there an algorithmic way to check if a dataset oscillates?
A simulation gives the population numbers for every species in the domain per frame. These vary over time and can be quite noisy, is there a way of analysing the data algorithmically without drawing a ...
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0answers
150 views
Dataset for percentage of population considered middle class per country? [closed]
I have found the WorldBank WDI useful in determining which countries are as a whole considered low, lower middle, upper middle and high income countries, but I would like data on the percentage of ...
1
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1answer
1k views
How to compare proportions across different groups with varying population sizes?
I am trying to understand what statistical measures I can use to compare three groups having varying populations to understand which group is bad (highest probability of death or most vulnerable or ...
3
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2answers
579 views
When the population has a known fixed size, are tables for the t statistic wrong?
As I understand it, Student's t will asymptotically approximate the Z statistic at sample sizes approaching infinity (see the infinite degrees of freedom row for degrees of freedom in most ...
2
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2answers
413 views
How to graphically compare distributions of a variable for two groups with different sample sizes?
I'm not familiar with statistics terminology, so I can't google it unless I know what it's called.
My problem is this: I have a "test" (for lack of a better term) where I ask people to choose an ...
3
votes
2answers
266 views
Time series data distribution forecast?
While having chronically data of population growth (registered users of a site), I want to compute a function that approximates future growth, based on past data. Also, what we ll be the distribution ...
5
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2answers
226 views
How is Google+ population estimated?
I keep reading that people are estimating the Google+ population based on statistical estimates:
My model is simple. I start with US Census Bureau data about surname popularity in the U.S., and ...
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1answer
299 views
Difference between population and sample
I have a general understanding of the difference between a population (set of entities under study) and a sample (a subsection selected from the population). However, I've been doing some work in PPC ...
