ans is 6 & 6. Why?
if you add 6 & 6 to the list the, avg does not change and adding the two #'s will actually make the std dev smaller because you have more #'s that are less from the mean(std dev).
certain list of 100 data...PT
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gmattester
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Vignesh.4384
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gmattester,
Take an eg of the set {2 4 6}
The mean will be 4.
The standard deviation can be found as [ (-2)^2 + 0^2 + (2)^2 /3 ]^1/2 (hope u get this step)
standard deviation = ( 8/3 ) ^ 1/2
When u add 4 and 4 to the set mentioned above ..
The standard deviation can be found as [ (-2)^2 + 0^2 + 0^2 + 0^2+ (2)^2 /5 ]^1/2
If u notice the denominator increases but numerator does not when 4 and 4 are added to {2 4 6}
Take an eg of the set {2 4 6}
The mean will be 4.
The standard deviation can be found as [ (-2)^2 + 0^2 + (2)^2 /3 ]^1/2 (hope u get this step)
standard deviation = ( 8/3 ) ^ 1/2
When u add 4 and 4 to the set mentioned above ..
The standard deviation can be found as [ (-2)^2 + 0^2 + 0^2 + 0^2+ (2)^2 /5 ]^1/2
If u notice the denominator increases but numerator does not when 4 and 4 are added to {2 4 6}
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gmattester
- Master | Next Rank: 500 Posts
- Posts: 172
- Joined: Wed Oct 31, 2007 11:21 am
- Thanked: 1 times
