"We usually assume that the distribution of <x> is Gaussian and that the margin of error, on each side is equal to the standard deviation, s, obtained from measurements. "
Do you mean the distribution of the individual values of x is Gaussian, or do you mean that the distribution the actual averages is Gaussian (i.e. you measured <x> several times and the distributions of those values of <x> follow a Gaussian distribution)? The "margin of error" for the distribution of x is s, but the "margin of error" of <x> is generally taken as s/(N^0.5) wher N is the number of values averaged to find <x>.
I think you mean the distribution of x(i) itself, but this distinction needs to be clear throughout the discussion.
Tim Folkerts
-----Original Message-----
From: phys-l-bounces@carnot.physics.buffalo.edu on behalf of Ludwik Kowalski
Sent: Wed 11/8/2006 9:21 PM
To: Forum for Physics Educators
Subject: [Phys-l] Basic statistics
I do not recall what motivated me. But I wrote a short essay on basic
statistics. Retired teachers like teaching. In any case, this essay is
now at:
Comments will be appreciated, especially if something is wrong. I will
be happy to correct mistake or add something that should be added. Keep
in mind, however, that a short essay is not a textbook.
P.S.
The Greek symbol delta (capital), in my htnl code, is Δ . And it
does the job, at least with my browser. But the code µ that was
expected to produce the Greek letter mu did not work. I do not know
why. So I just typed mu. Little help with html coding for Greek symbols
will be appreciated, preferably in the form of examples that are known
to work on most browsers.
PPS
Even if you do not care about my essay, do not miss the URL for a great
statistical calculator that can be used over the Internet. It is much
more convenient than z and t distributions tables. Try it at: