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Topic: Re[2]: Pr(Z<...) How much by hand.
Replies: 1   Last Post: Nov 6, 1996 10:47 AM

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 Pat Ballew Posts: 356 Registered: 12/3/04
Re[2]: Pr(Z<...) How much by hand.
Posted: Nov 6, 1996 7:38 AM

I certainly agree with Prof. Hayden that the tables can present
obstacles, and I agree that sometimes the number is all we are after
because we want to focus on what it means, not where it came from.
My point was that the tables, in consort with the calculator,
offer the chance for both a global and point perspective. Perhaps
this can be done by more experienced or capable teachers without the
table, but I find they seem to help me point out ideas that I feel are
important for my students.

Pat Ballew
Misawa, Japan

Subject: Re: Pr(Z<...) How much by hand.
Author: Bob Hayden <hayden@oz.plymouth.edu> at EDU-INTERNET
Date: 11/5/96 3:09 PM

----- Forwarded message from Pat_Ballew@ccmail.odedodea.edu -----

ON TABLES I think tables still have a use, at least for a
while, both in trig and in Stats. I still like the global impact
of seeing sin cos across the top of a row and cos sin across the
bottom. I especially like the tables that only go to 45 degrees
and have 0-45 down on one side and 45-90 up the other.
In statistics, I like to have students look at a table
that shows lots of values at one time for the same reason. I am
partial to tables that have
z and -z and their probabilities in adjacent columns. This I
think helps drive home one type of important symmetry, that P(-z)
+ P(z) = 1 or in its more usable form p(-z) = 1-P(z). It is a
hard thing to overlook in those long columns.

----- End of forwarded message from Pat_Ballew@ccmail.odedodea.edu -----

My preferences are quite the opposite, but I can see Pat's point. My
problem with these complicated folded tables is that you start out
trying to teach something about uses of the normal distribution and
you end up spending all your time dealing with the peculiarities of
the particular table you are using. Siegel and Morgan sacrifice space
to simplicity in the normal table they give in their textbook. I like
it. After students can read that table, you might want to go on and
show how they could have saved some space by taking advantage of
certain symmetries. I find trying to do everything at once loses the
students I have.

_
| | Robert W. Hayden
| | Department of Mathematics
/ | Plymouth State College MSC#29
| | Plymouth, New Hampshire 03264 USA
| * | Rural Route 1, Box 10
/ | Ashland, NH 03217-9702
| ) (603) 968-9914 (home)
L_____/ hayden@oz.plymouth.edu
fax (603) 535-2943 (work)

Date Subject Author
11/6/96 Pat Ballew
11/6/96 Chris Olsen