-
mlane25269
- Master | Next Rank: 500 Posts
- Posts: 151
- Joined: Fri Jun 13, 2008 7:31 am
- Thanked: 1 times
GMATprep PS question
This topic has expert replies
Source: Beat The GMAT — Problem Solving |
-
smashinonions
- Junior | Next Rank: 30 Posts
- Posts: 22
- Joined: Tue Jul 03, 2007 11:23 pm
- Thanked: 1 times
is it 6 and 6 ??
------------------------------------------------------
Five years ago: GMAT - 740
Five years later: 1st Attempt - 620
GOING for 2nd attempt: Target - 740
Five years ago: GMAT - 740
Five years later: 1st Attempt - 620
GOING for 2nd attempt: Target - 740
-
ildude02
- Master | Next Rank: 500 Posts
- Posts: 320
- Joined: Sun Jan 13, 2008 10:00 pm
- Thanked: 10 times
The answer is E, since the pair 6, 6 both are the avg values and would not change the average and also the variance = (each value - mean) ^ 2 for the new values will be 0. But the num of data incresed from 100 to 102, so the SD which is
SQRT(sum of variance of each individual element/num of elements) will now be less then before.
Any easier way of getting to the answer?
SQRT(sum of variance of each individual element/num of elements) will now be less then before.
Any easier way of getting to the answer?
-
mlane25269
- Master | Next Rank: 500 Posts
- Posts: 151
- Joined: Fri Jun 13, 2008 7:31 am
- Thanked: 1 times
I hope there is an easier way because I sure am confused on this one. I had thought that standard deviation was rarely tested on the GMAT and yet the GMATprep has about 3 or 4 standard deviation questions??
