Re: Is this correct?

DarkProtoman skreiv:

I was doing some work from a "Statistics for Dummies" book, and I
calculated this for a sample I picked out of my head:

Sample: 1,2,4,8,16
Mean: 6.2

Correct.

SD: 3.05

No, it is ~6.1.

SE: 1.36

No, it is ~2.7. But the relationship between your SD and your SE is correct.

t-scores: 33,36,43,56,82

No, these doesn't make much sense.

Are these correct? And what does the 't' in t-score mean?

It was originally a z, if that helps. :)

See:

On the Transition from "Student's" z to "Student's" t
Churchill Eisenhart
The American Statistician, Vol. 33, No. 1. (Feb., 1979), pp. 6-10.

Stable URL:
http://links.jstor.org/sici?sici=0003-1305%28197902%2933%3A1%3C6%3AOTTF%22Z%3E2.0.CO%3B2-3

Abstract: The change from the z of "Student's" 1908 paper to the t of
present day statistical theory and practice is traced and documented. It is
shown that the change was brought about by the extension of "Student's"
approach, by R.A. Fisher, to a broader class of problems, in response to a
direct appeal from "Student" for a solution to one of these problems.

And, I've always wondered this, but what is the physical meaning of
standard deviation?

It is, loosely speaking, the square root of the average squared distance
from the mean.

How would I use it to figure out, for example, how many
bolts to discard, based on their length? Thanks!!!!

That would of course depend on what you will use the bolts for. :)

--
Karl Ove Hufthammer
.

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