GMAT PREP : STAND DEV question:

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Source: — Data Sufficiency |

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by cris » Tue Feb 05, 2008 10:41 am
If the corret answer is A I will gladly explain...

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by GMATDUD » Tue Feb 05, 2008 10:57 am
yep it is A.

My guess was if water is removed in equal quantities the SD would not change. Not too sure if the law of weighted averages would hold when we use the sq root to determine the SD.

Your Thoughts?