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Context of this question is not clear because it is NOT a full question. However
when attempting to estimate an parameter such as µ using sample data when
the population standard deviation σ is unknown, we have to estimate the standard
deviation of the population using a stastitic called s where
_
Σ(x-x)²
s = ▬▬▬▬
n -1
_
and estimator for µ , in particular x
........................................._
has a standard deviation of s(x)= s/√n
and the statistic
_
x - hypothesized µ
T = ▬▬▬▬▬▬▬▬▬▬
s
has a student's T distribution with n-1 degrees of freedom
If n> 30 , then by the Central Limit Theorem, the T distribution
approaches the shape and form of the normal(gaussian) probability
distribution and the Z table may be used to find needed critical statistical
values for hypothesis tests , p-values, and interval estimates.
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What is the symbol for population standard deviation?
Sigma
Is standard deviation same as standard error?
From what ive gathered standard error is how relative to the population some data is, such as how relative an answer is to men or to women. The lower the standard error the more meaningful to the population the data is. Standard deviation is how different sets of data vary between each other, sort of like the mean. * * * * * Not true! Standard deviation is a property of the whole population or distribution. Standard error applies to a sample taken from the population and is an estimate for the standard deviation.
You take an SRS of size n from a population that has mean 80 and standard deviation 20 How big should n be so that the sampling distribution has standard deviation 1?
400
If quartile deviation is 24. find mean deviation and standard deviation?
Information is not sufficient to find mean deviation and standard deviation.
When do you know when to use t-distribution opposed to the z-distribution?
z- statistics is applied under two conditions: 1. when the population standard deviation is known. 2. when the sample size is large. In the absence of the parameter sigma when we use its estimate s, the distribution of z remains no longer normal but changes to t distribution. this modification depends on the degrees of freedom available for the estimation of sigma or standard deviation. hope this will help u.... mona upreti.. :)
The standard deviation of the distribution of means is also known as the population standard deviation?
Yes.
What does the sample standard deviation best estimate?
The standard deviation of the population. the standard deviation of the population.
When the population standard deviation is not known the sampling distribution is a?
If the samples are drawn frm a normal population, when the population standard deviation is unknown and estimated by the sample standard deviation, the sampling distribution of the sample means follow a t-distribution.
When the population standard deviation is known the sampling distribution is known as what?
normal distribution
When the population standard deviation is known the sampling distribution is a?
normal distribution
Is population standard deviation the same thing as absolute standard deviation?
No.
Can a standard deviation of a sample be equal to a standard deviation of a population?
Yes
What is the standard deviation of 157 160 161 172 165 149?
The standard deviation if the data is a sample from a population is 7.7115; if it is the population the standard deviation is 7.0396.
What is the statistic that is used to estimate a population standard deviation?
the sample standard deviation
How do i find sample standard deviation from population standard deviation?
If the population standard deviation is sigma, then the estimate for the sample standard error for a sample of size n, is s = sigma*sqrt[n/(n-1)]
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
The population standard deviation is 100?
It can be.
