GMATprep SD

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Source: — Problem Solving |

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by sudhir3127 » Mon Jul 14, 2008 9:58 pm
My answer is 12

1 standard deviation below mean is 21 -6 = 15.
2 standard deviations below mean is 21 -2*6 = 9.
So Pat's hours must be between 9 and 15. Only 12 falls in this range.

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by ksh » Mon Jul 14, 2008 11:20 pm
Thanks.

I didnt understand the wording. its damn easy !!