statistics: sample median, means, s.d. vs sample size


by jhson114
Tags: means, median, sample, size, statistics
jhson114
jhson114 is offline
#1
Oct23-05, 08:35 PM
P: 82
i have a set containing 10000 data. i took 1000 samples of size 4, 16, 64, and 1024 and took the medians, means, and stadard deviations of each size. i graphed them sd of medians vs sample size, sd of mean vs sample size, and sd of s.d. vs sample size. for sample mean, i know from a text book that:
SD of sample means = population SD / sqrt(sample size n).
But it seems from the graph i created using R, sd of medians and s.d. vs sample size all have the exact same looking graph, which to me suggests that:
SD of sample means, medians, and s.d. = population SD / sqrt(sample size n).
Is this right? it seems a little awkward. any input will be very helpful. thank you
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EnumaElish
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#2
Oct24-05, 10:25 PM
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graph i created using R
What is R?

More generally, is your question whether the "sample vs. population" formula (sample stat = population stat/sqrt(n)) applies to median and std. dev. in addition to the mean?
jhson114
jhson114 is offline
#3
Oct25-05, 05:57 PM
P: 82
R is just a program language kind of like matlab.

"More generally, is your question whether the "sample vs. population" formula (sample stat = population stat/sqrt(n)) applies to median and std. dev. in addition to the mean?"

This is exact what i'm asking.


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