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From: anthony@utcsstat.UUCP (Anthony Ayiomamitis)
Newsgroups: net.math
Subject: significant digits
Message-ID: <2244@utcsstat.UUCP>
Date: Wed, 21-Aug-85 10:58:21 EDT
Article-I.D.: utcsstat.2244
Posted: Wed Aug 21 10:58:21 1985
Date-Received: Wed, 21-Aug-85 11:35:10 EDT
Organization: U. of Toronto, Canada
Lines: 28

>> The usual method of writing numbers (e.g. 10, .007) carries no information
>> about accuracy.  .007 could be accurate to one, two or three decimal places.
>
>	This is getting rather off the point, but some of you might like
>this.  During one of my interviews for college, I was asked a typical
>stupid interview question: "What's the area of a table 3 meters wide by 4
>meters long?"  I poked around with various counter-probes like, "Do you
>mean the area of just the top surface, or the top and bottom combined?" and
>then came up with the obvious answer; 12 meters^2.
>
	If someone tells me that something measures 3 by 4, I cannot tell
whether they really mean 3 by 4, or 3.00 by 4.00, or 3.000 by 4.0, etc.
However, the implicit assumption is that these dimensions are exact and,
hence, a "reasonable" reply would be 12 square meters. Of course, if this
question was asked on a written exam in the form of "3 by 4", then an
answer of 1*10^1 square meters is indeed perhaps more appropriate.

>	Anyway, it turns out the "correct" answer is 1 * 10^1 meters^2;
>since the initial data only had 1 digit of accuracy, that's all the final
>answer can have.
>-- 
>Roy Smith 
>System Administrator, Public Health Research Institute
>455 First Avenue, New York, NY 10016
-- 

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