Set M contains a set of consecutive integers. What is the standard deviation of set M?

(1) Set M contains 17 numbers

(2) The median of set M is 23

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## April 9th GMAT Question of the Day Solution:

Consecutive sets have special properties.

1. Median = Mean = (Max + Min)/2

2. Any consecutive set with the same number of numbers has the same standard deviation. For instance: The set 1, 2, 3 has the same standard deviation as 51, 52, 53 as will any set of 3 consecutive integers. So if you know the number of numbers you can figure out the standard deviation.

Statement (1) gives us the number of numbers in the set. **Sufficient.**

Statement (2) only gives us the median. The set could could be 22, 23, 24 or 21, 22, 23, 24, 25. These two sets have different standard deviations. **Insufficient.**