 
 
 
 
 
 
Maen
- To: mathgroup at smc.vnet.net
- Subject: [mg48119] Maen
- From: per.ronne at doesnt.work.spam.filter.invalid
- Date: Fri, 14 May 2004 00:13:44 -0400 (EDT)
- Reply-to: spam at husumtoften.dk
- Sender: owner-wri-mathgroup at wolfram.com
I've just purchased Mathematica 5 but I've got some problems.
I write:
boys = 
  {192, 176, 178, 180, 189, 173, 177, 176, 176, 194,
    178, 172, 175, 180, 170, 174, 180, 184, 177, 181,
    190, 186, 187, 184, 190, 180, 178, 182, 181, 180,
    175, 182, 182, 181, 179, 190, 173, 189, 173, 183,
    172, 178, 182, 172, 190, 180, 176, 177, 181, 185,
    174, 178, 178, 178, 170, 175, 178, 186, 185, 182,
    179, 187, 183, 188, 191, 180, 193, 183, 185, 174,
    174, 180, 191, 180, 177, 185, 192, 187, 170, 176,
    170, 184, 179, 173, 184, 184, 190, 179}
But when I try to get their average height [it is the height of boys in
Danish upper grammar schools, grade 13 at the age of around 19], I get:
Mean[boys]
Mean[{192, 176, 178, 180, 189, 173, 177, 176, 176, 194, 178, 172, 175,
180, 
    170, 174, 180, 184, 177, 181, 190, 186, 187, 184, 190, 180, 178,
182, 181,
     180, 175, 182, 182, 181, 179, 190, 173, 189, 173, 183, 172, 178,
182, 
    172, 190, 180, 176, 177, 181, 185, 174, 178, 178, 178, 170, 175,
178, 186,
     185, 182, 179, 187, 183, 188, 191, 180, 193, 183, 185, 174, 174,
180, 
    191, 180, 177, 185, 192, 187, 170, 176, 170, 184, 179, 173, 184,
184, 190,
     179}]
And it doesn't help to put on a //N:
Mean[boys] // N
Mean[{192., 176., 178., 180., 189., 173., 177., 176., 176., 194., 178.,
172., 
    175., 180., 170., 174., 180., 184., 177., 181., 190., 186., 187.,
184., 
    190., 180., 178., 182., 181., 180., 175., 182., 182., 181., 179.,
190., 
    173., 189., 173., 183., 172., 178., 182., 172., 190., 180., 176.,
177., 
    181., 185., 174., 178., 178., 178., 170., 175., 178., 186., 185.,
182., 
    179., 187., 183., 188., 191., 180., 193., 183., 185., 174., 174.,
180., 
    191., 180., 177., 185., 192., 187., 170., 176., 170., 184., 179.,
173., 
    184., 184., 190., 179.}]
If I look up in the Stephen Wolfram's Mathematica book 5th Edition on
page 109, it should be possible to get:
data = {4.7, 7.2, 8.4, 5.8, 9.2, 3.9}
Mean[data]
6.46667
But instead I get:
Mean[{4.7, 7.2, 8.4, 5.8, 9.2, 3.9}]
What is wrong?
-- 
Per Erik Rønne
- Follow-Ups:

