I am not exactly certain, but I believe from what I encountered, and what I saw on the first exam I took. Yes, I did take it once already, its been a few months since. Without getting myself in trouble (copyright), I think the questions mightbe something like this:
A number is added to a set, which of the following must be true if the SD of the set increased.
Or they might list numbers in 5 different sets, and ask for the one with greatest SD, lowest, and so on.
Think about it, bottom line is, I dont think they'll ask to calculate SD or anything of that nature, but they might ask questions that test the knowledge of relationship between the numbers, sets, what happens to SD when Range increases/decreases and so on.
Hope that helps,
PS It really would be helpful if many of us here added their bit to this question. I definitely think its an important one
. (One, right?, or is it, An important question?) Hmm, I think I've been studying for GMAT too much