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Topic: Rules for Variances
Replies: 2   Last Post: Mar 13, 1996 6:37 PM

 Messages: [ Previous | Next ]
 John Chappelle Posts: 4 Registered: 12/6/04
Rules for Variances
Posted: Mar 13, 1996 12:04 PM

IPS pg. 332 gives rules for variances. The rule for linear transformations
is easy to demonstrate; however I am having problems with the addition of
variances when adding data sets. It is fairly easy to show that the spreads
of the values are additive and I am working on a spreadsheet simulation
which should show that the variances are additive inductively. When I
demonstrate this inductively I like to give an algebraic proof for those who
can follow it but I cannot find/figure-out one. Can anyone help? How do
you justify using the addition of variances when comparing two mean? I
would be interested in any ideas you have for teaching this material to high
school students.

Thanks

John C. Chappelle jchappel@mindspring.com
Brookstone School Tele: 706-660-9731 (W)
440 Bradley Park Dr Tele: 706-323-8307 (H)
Columbus, Ga 31904-2989 FAX: 706-660-9731

Date Subject Author
3/13/96 John Chappelle
3/13/96 Chris Olsen
3/13/96 Chris Olsen