Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site utcsstat.UUCP Path: utzoo!utcs!utcsstat!anthony 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 -- {allegra,ihnp4,linus,decvax}!utzoo!utcsstat!anthony {ihnp4|decvax|utzoo|utcsrgv}!utcs!utzoo!utcsstat!anthony