# Questions tagged [population]

A population is the entire set of units from which a sample may be drawn.

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### How to interpret 'e' in Yamane's Formula?

If I use e=0.05, and from Yamane's formula I obtain, say, a sample size of 300 from given population size. Now, for instance, I obtain some descriptive statistics from the sample size such as the mean ...
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### two proportion z test with large population

I want to test for differences between two proportions, specifically, a complete count of the number of events occurring within a population in year 1 vs that in year 2. I thought a two proportion z ...
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### Why do 95% confidence intervals contain the unknown population mean 95% of the time?

I am learning about the Central Limit Theorem (CLT) and confidence intervals from this online course. I have learnt that that the CLT states that the theoretical sampling distribution of a sample ...
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### When we up-sample the training set, don't we introduce selection bias?

When doing supervised machine learning in the health or medical domains, we often have a target class that is relatively rare (e.g., prevalence 1-10% of cases). There are a few techniques we can do to ...
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### How to study data variance with significant and non-significant regression response?

Background My research field is within development of Finite Element Human Body Models (FE-HBMs) with the aim of including geometrical population variance (3D shape). My background is not in ...
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### Practical use for heritability value at sub-population level?

For me as a layperson, heritability is something that much smarter people than me calculate, and there are several questions already on the forum about how to do that (eg, this and this). I ...
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### Stratified Sampling from a population according to given weights

I have a population and i want to take a sample from it in order to examine a mean of a characteristic (say $p$ the probability of having an infringment).My population is 13996 and are divided into 7 ...
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### How can you compare changes in a shifting population over time?

How can you compare changes in shifting population over time? For instance, say I have the proportion of retired people in a town at time 1 (T1), then again at time 2 (T2). The "population" ...
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### Central Limit Theorem: Is the likelihood of obtaining some sample mean exact when n is not infinity?

The central limit theorem states: $$\lim _{n\to \infty}{\sqrt{n}}{\left({\frac {{\bar {X}}_{n}-\mu }{\sigma }}\right)} \sim \mathcal{N}(0,1)$$ Which means if I ran an infinite number of experiments, ...
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### What do "random sample" and "particular population" mean in clustering?

Yesterday, from a suggestion of @Dimitriy V. Masterov here, I saw from the given link about one of the reason we can avoid clustering is You want to say something about the association between ...
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### How to test if the subset is representative to whole dataset

I would like to ask how to test if the subset is representative to the whole dataset. I have for example 150 values in whole "population" and I selected (not randomly) 30 of them. I would ...
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### how to test auto-selected sample and modify it to represent population

Suppose you have responses from a survey on an entire population, i.e. an organization of 5000 people. All has been invited to respond. Only 65% of them did. Assume also you have the ground truth of ...
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### How to compare sample and population characteristics?

I have a sample $S1$ of 200 people, and I obtained a subsample $S2$ of 100 people by emailing a survey link to $S1$. So, $S2$ is a nonrandom subsample drawn without replacement. In the sample $S1$, I ...
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### Terminology - population and sample in repeated rolling dice experiments

The the law of large numbers wikipedia page has an example on fair, six-sided dice: According to the law of large numbers, if a large number of fair six-sided dice are rolled, the average of their ...
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### Determine item level variance of single test administrations as well as of an entire sample of administrations

I am decades out of school and need help determining the correct statistic / concept to use for my use case. My agency (human services) uses a specific functional test to determine how well clients ...
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### How statistically relevant are COVID information about the number of infections per day?

I am French and the restrictions in place in my country are driven by several indicators, including "the total number of infections per day". For reference, it is currently given as about ...
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### Is “$\mu_{\bar{x}} = \mu$” the same thing as saying the mean of the population is the same as the mean of the sample?

My e-textbook is telling me that, when finding a sample from a population using a normal probability distribution $\mu_{\bar{x}}$ is roughly equal to $\mu$. It then gives me a problem asking me to ...
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### How to forecast temporal series and have them match with external values?

I have a hierarchical population dataset with 3 grouping variables (Age, Gender and Urban/Rural Setting). I would like to generate predictions at the bottom-level (i.e. disaggregated at Age * Gender * ...
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### Is there a difference between a population and a set of realisations of a random variable?

Is there a difference between a population and a set of realisations of a random variable? I heard that a sample of a random variable is a set of iid duplicates of the random variable as a process, or ...
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### How do we decide when a small sample is statistically significant or not?

Sorry if the title isn't clear, I'm not a statistician, and am not sure how to phrase this. I was looking at the global coronavirus statistics on worldometers, and sorted the table by cases per ...
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### statistical method for finding significant numbers in a set [closed]

Suppose that we have a population of $N= 1000$ people and they want to select 5 items (for simplicity) $\{A, B, C, D, E\}$ (but actually number of items is in the order of thousands). Number of ...
548 views

### Is heights of humans actually a discrete random variable? [duplicate]

Suppose the human population consisted of $N = 3$ people, each with a specific height. Let $X^N$ be the random variable representing the heights of this population of $N$ people. Since $X^N$ can only ...
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### Population vs. Data-Generating Process

A lot of elementary statistical and econometric literature bases on so called "population models". An example is econometric handbook "Introductory Econometrics: A Modern Approach" ...
Let's say I have a population {$(G, p)$} where $G$ is a group within the population, and $p$ is their proportion distributed as such: ...