Hi Anaira Mitch,
From the prompt, we can calculate the MEAN of the original 5 values... -5/5 = -1. We're asked for the percentage change in the MEAN after we remove two of the numbers from the original set:
{-10,-8, 0, 6, 7}
1) The median of the set will remain the same.
The current median is 0. If the median remains the same after removing the two values, then we could end up with a four different groups:
{-10, 0, 6] Avg = -4/3
{-10, 0, 7} Avg = -3/3 = -1
{-8, 0, 6} Avg = -2/3
{-8, 0, 7} Avg = -1/3
Each of these groups has a different average, so the percentage change would be different for each.
Fact 1 is INSUFFICIENT
2) The range of the set will decrease by 3.
The current range is 7 - (-10) = 17. If we decrease that value by 3, we'll end up with a range of 14. With the set of numbers that we're working with, there's only one sub-group that can occur:
{-8, 0 , 6}
Fact 2 is SUFFICIENT
Final Answer: B
GMAT assassins aren't born, they're made,
Rich
