BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Need Help With This One. Can someone please explain.

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Problem Solving |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pm
Location: Vancouver, BC
Thanked: 5254 times
Followed by:1268 members
GMAT Score:770

by Brent@GMATPrepNow » Tue Oct 08, 2013 8:18 am
inavdeep wrote:If M is a negative integer and K is a positive integer, which of the following could be the standard deviation of a set {-7, -5, -3, M, 0, 1, 3, K, 7}?

I. -1.5
II. -2
III. 0


(A) I only (B) II only (C) III only (D) I and III only (E) None

Answer is E.
Nice question

The standard deviation is always greater than or equal to 0. So, ELIMINATE I and II.
The standard deviation equals 0 only when all of the values in the set are the same. This is clearly not the case, so the standard deviation cannot equal 0. ELIMINATE III.

This leaves us with E

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image
Top
Post new topic Post Reply
• Page 1 of 1