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When performing an experiment or gathering data for statistics, it would be very difficult to gather information for every member of the group's population. Instead, one can gather information from a sample large enough to be representative of the population.
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What does n-1 indicate in a calculation for variance?
The n-1 indicates that the calculation is being expanded from a sample of a population to the entire population. Bessel's correction(the use of n − 1 instead of n in the formula) is where n is the number of observations in a sample: it corrects the bias in the estimation of the population variance, and some (but not all) of the bias in the estimation of the population standard deviation. That is, when estimating the population variance and standard deviation from a sample when the population mean is unknown, the sample variance is a biased estimator of the population variance, and systematically underestimates it.
Difference between sample regression and population regression line?
AnswerA sample is a subset of a population. Usually it is impossible to test an entire population so tests are done on a sample of that population. These samples can be selected so that they are representative of the population in which cases the sample will have weights, strata, and clusters. But usually people use random samples. So it's not that the line is different, it's that the line comes from different data. In stats we have formulas that allow a sample to represent a population, if you have the entire population (again unlikely), you wouldn't need to use this sample formulas, only the population formulas.
What are some assumptions that must be made in order to use a sample to describe a population?
Some assumptions that must be made in order to use a sample to describe a population is to ensure that an accurate sample of the population has been taken. Some factors that must be taken in to account include: gender, race, ethnicity, age, and any other factors that may affect the outcome of the total population. Also the number of sample in relation to the population is also a big factor. Usually, census services use population ratios of per 1000 people.
What sentence is a true statement Is a sample a subset of the population or Is a population a subset of the sample?
A sample is a subset of the population.
How is a sample different from a population?
The sample is a subset of the population.
What would a sampling error of zero mean?
The sampling error is the error one gets from observing a sample instead of the whole population. The bigger it is, the less faith you should have that your sample represents the true value in the population. If it is zero, your sample is VERY representative of the population and you can trust that your result is true of the population.
Does a Quota Sample represent the whole population?
yes because the quota sample include the random sample and when we have over estimation we will use the quota sample
What will happen if the sample you have drawn from the population does not represent the population?
You are studying the sample because you want to find out information about the whole population. If the sample you have drawn from the population does not represent the population, you will find out about the sample but will not find out about the population.
How is a sample related to a population?
A sample is a subset of the population.
When to use z or t-distribution?
If the sample size is large (>30) or the population standard deviation is known, we use the z-distribution.If the sample sie is small and the population standard deviation is unknown, we use the t-distribution
Is the data is sample or population?
Data is neither sample nor population. Data are collected for attributes. These can be for a sample or a population.
What does it mean for a sample to representative of a population?
That the key characteristics of the population are reflected in the sample.
What is the relationship between sample and population?
From a sample of a population, the properties of the population can be inferred.
What is the the relationship between population and sample parameter and statistic?
The relations depend on what measures. The sample mean is an unbiased estimate for the population mean, with maximum likelihood. The sample maximum is a lower bound for the population maximum.
What is a random sample from a population?
A random sample is a sample (subset of the population) where each member of the population has an equal chance of being sampled. See related links.
Does a parameter describe a population or a sample?
A parameter describes a population. A statistic describes a sample.
Why is it only possible to estimate the mean median and quartiles?
In reality, a statistician never really has ALL the data. The data is instead taken from a sample of the whole population. If this sample is representative of the entire population, then any statistics based on the sample should be good estimates of the whole but probably not a perfect match. Of course the more data you get from the whole population the better the estimate, but it will always be an estimate unless you census the enitire population.
