December 11, 2018 December 11, 2018 09:00 PM EST 10:00 PM EST Strategies and techniques for approaching featured GMAT topics. December 11 at 9 PM EST. December 13, 2018 December 13, 2018 08:00 AM PST 09:00 AM PST What people who reach the high 700's do differently? We're going to share insights, tips and strategies from data we collected on over 50,000 students who used examPAL.
Author 
Message 
TAGS:

Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 51096

Which of the following sets has the greatest standard deviation?
[#permalink]
Show Tags
19 Dec 2016, 08:43
Question Stats:
87% (01:02) correct 13% (01:10) wrong based on 86 sessions
HideShow timer Statistics
Which of the following sets has the greatest standard deviation? A. {1, 4, 12, 16, 17} B. {3, 4, 7, 18, 18} C. {2, 5, 13, 17, 23} D. {50, 2, 33, 34, 35} E. {0, 0, 0, 19, 31}
Official Answer and Stats are available only to registered users. Register/ Login.
_________________
New to the Math Forum? Please read this: Ultimate GMAT Quantitative Megathread  All You Need for Quant  PLEASE READ AND FOLLOW: 12 Rules for Posting!!! Resources: GMAT Math Book  Triangles  Polygons  Coordinate Geometry  Factorials  Circles  Number Theory  Remainders; 8. Overlapping Sets  PDF of Math Book; 10. Remainders  GMAT Prep Software Analysis  SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS)  Tricky questions from previous years.
Collection of Questions: PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.
What are GMAT Club Tests? Extrahard Quant Tests with Brilliant Analytics



Senior Manager
Joined: 24 Oct 2016
Posts: 268
Location: India
Concentration: Finance, International Business
GPA: 3.96
WE: Human Resources (Retail Banking)

Re: Which of the following sets has the greatest standard deviation?
[#permalink]
Show Tags
19 Dec 2016, 09:54
By calculating mean of each Set and then checking which no. Is farther from mean we just left with option D Sent from my HM 1SW using GMAT Club Forum mobile app



Senior Manager
Joined: 13 Oct 2016
Posts: 367
GPA: 3.98

Which of the following sets has the greatest standard deviation?
[#permalink]
Show Tags
19 Dec 2016, 09:59
Standard deviation is a square root of the sum of squired differences between elements of the set and set’s mean divided by the # of elements. Wordy, but the logic is that the greater the difference of the elements from the mean the greater the deviation. If set contains some “peaks” which are far from the mean, this distance will be squared in calculation of the variation.
All the given sets have similar means, its value will be somewhere between 8 and 12. But set D has negative element 50, which when deducted from he mean and then squared will add rather big value to our variation \((60 + something)^2\).
Thus, answer is D



Target Test Prep Representative
Status: Head GMAT Instructor
Affiliations: Target Test Prep
Joined: 04 Mar 2011
Posts: 2830

Re: Which of the following sets has the greatest standard deviation?
[#permalink]
Show Tags
03 Jan 2017, 16:47
Bunuel wrote: Which of the following sets has the greatest standard deviation?
A. {1, 4, 12, 16, 17} B. {3, 4, 7, 18, 18} C. {2, 5, 13, 17, 23} D. {50, 2, 33, 34, 35} E. {0, 0, 0, 19, 31} The standard deviation is a sophisticated measure that relies in part on the distance of each data value from the mean. In general, the farther the data values are from the mean, the larger the standard deviation. So, let’s find the mean of each data set first. A. (1 + 4 + 12 + 16 + 17)/5 = 50/5 = 10 B. (3 + 4 + 7 +18 +18)/5 = 50/5 = 10 C. (2 + 5 + 13 + 17 + 23)/5 = 50/5 =10 D. (50 + 2 + 33 + 34 + 35)/5 = 50/5 = 10 E. (0 + 0 + 0 + 19+ 31)/5 = 50/5 = 10 As we can see, all the data sets have a mean of 10. Now, for each data set, we need to find how far away each value is from the mean. Let’s look at the data sets again. A. {1, 4, 12, 16, 17} B. {3, 4, 7, 18, 18} C. {2, 5, 13, 17, 23} D. {50, 2, 33, 34, 35} E. {0, 0, 0, 19, 31} As we can see, the data values from set D are the farthest from its mean out of all the data sets (four of its 5 values, 50, 33, 34, and 35, are farther from 10 than any values in the other data sets); thus, set D has the greatest standard deviation. Answer: D
_________________
Jeffery Miller
Head of GMAT Instruction
GMAT Quant SelfStudy Course
500+ lessons 3000+ practice problems 800+ HD solutions



Intern
Joined: 19 Apr 2017
Posts: 35
Location: India
WE: Management Consulting (Consulting)

Which of the following sets has the greatest standard deviation?
[#permalink]
Show Tags
24 Jun 2018, 23:58
JeffTargetTestPrep wrote: Bunuel wrote: Which of the following sets has the greatest standard deviation?
A. {1, 4, 12, 16, 17} B. {3, 4, 7, 18, 18} C. {2, 5, 13, 17, 23} D. {50, 2, 33, 34, 35} E. {0, 0, 0, 19, 31} The standard deviation is a sophisticated measure that relies in part on the distance of each data value from the mean. In general, the farther the data values are from the mean, the larger the standard deviation. So, let’s find the mean of each data set first. A. (1 + 4 + 12 + 16 + 17)/5 = 50/5 = 10 B. (3 + 4 + 7 +18 +18)/5 = 50/5 = 10 C. (2 + 5 + 13 + 17 + 23)/5 = 50/5 =10 D. (50 + 2 + 33 + 34 + 35)/5 = 50/5 = 10 E. (0 + 0 + 0 + 19+ 31)/5 = 50/5 = 10 As we can see, all the data sets have a mean of 10. Now, for each data set, we need to find how far away each value is from the mean. Let’s look at the data sets again. A. {1, 4, 12, 16, 17} B. {3, 4, 7, 18, 18} C. {2, 5, 13, 17, 23} D. {50, 2, 33, 34, 35} E. {0, 0, 0, 19, 31} As we can see, the data values from set D are the farthest from its mean out of all the data sets (four of its 5 values, 50, 33, 34, and 35, are farther from 10 than any values in the other data sets); thus, set D has the greatest standard deviation. Answer: D Jeff, for options C and D, I am getting a total of 60 and 54, resulting in a mean of 12 and 10.8 respectively. But even then, option D has the highest deviation. Am I doing something wrong?



Manager
Joined: 13 Feb 2018
Posts: 135

Re: Which of the following sets has the greatest standard deviation?
[#permalink]
Show Tags
25 Jun 2018, 03:21
Is it necessary to calculate mean? At a glance it was obvious that Set D had the most scattered vaues




Re: Which of the following sets has the greatest standard deviation? &nbs
[#permalink]
25 Jun 2018, 03:21






