If the number 58 is 1 std dev below the mean & the : Quant Question Archive [LOCKED]
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# If the number 58 is 1 std dev below the mean & the

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Intern
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If the number 58 is 1 std dev below the mean & the [#permalink]

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17 Apr 2006, 22:39
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

If the number 58 is 1 std dev below the mean & the number 98 is 2 std dev above the mean, then what is the mean value?

a. 70
b 72
c 74
d 78
VP
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17 Apr 2006, 23:53
m - 2d = 58 [m= mean, d=standard dev]
m + 3d = 98

Solving for m, we get 74

Hence C

Its qte easy if the theory behind SD is known!
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18 Apr 2006, 00:19
discussed recently ))
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IE IMBA 2010

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18 Apr 2006, 00:50
Yep. I posted there also!! :p
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18 Apr 2006, 01:39
how were you able to set up the equations -2dand +3d
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18 Apr 2006, 01:47
This is the original problem that I answered!
http://www.gmatclub.com/phpbb/viewtopic ... highlight=

U are rite... it shud be

m -1d =58
m+2d = 98

but then u do not get the value of m as one of the given nos. So I think the above link has the correct version of the question!
18 Apr 2006, 01:47
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