GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 15 Dec 2018, 08:09

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Events & Promotions

Events & Promotions in December
PrevNext
SuMoTuWeThFrSa
2526272829301
2345678
9101112131415
16171819202122
23242526272829
303112345
Open Detailed Calendar
• \$450 Tuition Credit & Official CAT Packs FREE

December 15, 2018

December 15, 2018

10:00 PM PST

11:00 PM PST

Get the complete Official GMAT Exam Pack collection worth \$100 with the 3 Month Pack (\$299)
• FREE Quant Workshop by e-GMAT!

December 16, 2018

December 16, 2018

07:00 AM PST

09:00 AM PST

Get personalized insights on how to achieve your Target Quant Score.

The arithmetic mean of set S is zero. If T = {-2.22; -1.96; -1.68; 1.6

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
TAGS:

Hide Tags

Intern
Joined: 05 Jan 2015
Posts: 49
Location: United States
WE: Consulting (Consulting)
The arithmetic mean of set S is zero. If T = {-2.22; -1.96; -1.68; 1.6  [#permalink]

Show Tags

Updated on: 22 Jun 2016, 05:44
6
00:00

Difficulty:

95% (hard)

Question Stats:

43% (02:26) correct 57% (02:28) wrong based on 97 sessions

HideShow timer Statistics

The arithmetic mean of set S is zero. If T = {-2.22; -1.96; -1.68; 1.62; 1.94; 2.16} is the subset of S consisting of all those elements in S which are more than two but less than three standard deviations away from the arithmetic mean of S, what could be equal to the standard deviation of S?

A) 0.54
B) 0.77
C) 0.82
D) 0.97
E) 1.62

Originally posted by riteshpatnaik on 21 Jun 2016, 21:37.
Last edited by Bunuel on 22 Jun 2016, 05:44, edited 1 time in total.
Renamed the topic, edited the question and added the OA.
Most Helpful Expert Reply
Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 8678
Location: Pune, India
Re: The arithmetic mean of set S is zero. If T = {-2.22; -1.96; -1.68; 1.6  [#permalink]

Show Tags

02 Aug 2016, 21:53
4
4
riteshpatnaik wrote:
The arithmetic mean of set S is zero. If T = {-2.22; -1.96; -1.68; 1.62; 1.94; 2.16} is the subset of S consisting of all those elements in S which are more than two but less than three standard deviations away from the arithmetic mean of S, what could be equal to the standard deviation of S?

A) 0.54
B) 0.77
C) 0.82
D) 0.97
E) 1.62

Imagine them on number line:

-2.22 ............. - 1.96 ............... - 1.68 ...........................................0 .......................................... 1.62 ..................... 1.94 .................... 2.16

Mean is 0.

Each of these elements is more than 2 SD away from mean. 1.62 is closest to mean 0 but it is more than 2 SD away from 0.
So 1 SD will be less than 1.62/2 = .81.

Similarly, each of these elements is less than 3 SD away from mean. - 2.22 is farthest from mean 0 but it is less than 3 SD away.
So 1 SD will be more than 2.22/3 = .74

There is only one options between .74 and .81 and that is .77.
Answer (B)
_________________

Karishma
Veritas Prep GMAT Instructor

Learn more about how Veritas Prep can help you achieve a great GMAT score by checking out their GMAT Prep Options >

General Discussion
Senior Manager
Joined: 23 Apr 2015
Posts: 305
Location: United States
Concentration: General Management, International Business
WE: Engineering (Consulting)
Re: The arithmetic mean of set S is zero. If T = {-2.22; -1.96; -1.68; 1.6  [#permalink]

Show Tags

22 Jun 2016, 04:06
Answer is D : 0.97.

(Bro, I'm not sure about this question, doesn't seems close to any questions i've seen so far, so giving it a shot)

I'm using the second part of the statement about the standard deviation. Using the standard Gaussian curve centered around Y axis with mean zero, +/- 2 sigma = 95% and +/-3 sigma = 99%, so the Standard deviation of the set should be between these, hence 0.97 or 97%

(Share a kudo's if you like the explanation)
Math Expert
Joined: 02 Sep 2009
Posts: 51218
Re: The arithmetic mean of set S is zero. If T = {-2.22; -1.96; -1.68; 1.6  [#permalink]

Show Tags

22 Jun 2016, 05:48
riteshpatnaik wrote:
The arithmetic mean of set S is zero. If T = {-2.22; -1.96; -1.68; 1.62; 1.94; 2.16} is the subset of S consisting of all those elements in S which are more than two but less than three standard deviations away from the arithmetic mean of S, what could be equal to the standard deviation of S?

A) 0.54
B) 0.77
C) 0.82
D) 0.97
E) 1.62

Edited the question.

PLEASE READ CAREFULLY AND FOLLOW: rules-for-posting-please-read-this-before-posting-133935.html
_________________
Intern
Joined: 05 May 2016
Posts: 36
Re: The arithmetic mean of set S is zero. If T = {-2.22; -1.96; -1.68; 1.6  [#permalink]

Show Tags

02 Aug 2016, 10:37
riteshpatnaik wrote:
The arithmetic mean of set S is zero. If T = {-2.22; -1.96; -1.68; 1.62; 1.94; 2.16} is the subset of S consisting of all those elements in S which are more than two but less than three standard deviations away from the arithmetic mean of S, what could be equal to the standard deviation of S?

A) 0.54
B) 0.77
C) 0.82
D) 0.97
E) 1.62

Quote:
Hello Experts:
Can you please provide answer to this question?
Thanks in advance.
Senior Manager
Joined: 23 Apr 2015
Posts: 305
Location: United States
Concentration: General Management, International Business
WE: Engineering (Consulting)
Re: The arithmetic mean of set S is zero. If T = {-2.22; -1.96; -1.68; 1.6  [#permalink]

Show Tags

02 Aug 2016, 10:47
Hi Yosita,

Let me know if this explanation is not clear enough.

Answer is D : 0.97.

(Bro, I'm not sure about this question, doesn't seems close to any questions i've seen so far, so giving it a shot)

I'm using the second part of the statement about the standard deviation. Using the standard Gaussian curve centered around Y axis with mean zero, +/- 2 sigma = 95% and +/-3 sigma = 99%, so the Standard deviation of the set should be between these, hence 0.97 or 97%
Manager
Joined: 12 Jun 2015
Posts: 79
Re: The arithmetic mean of set S is zero. If T = {-2.22; -1.96; -1.68; 1.6  [#permalink]

Show Tags

02 Aug 2016, 21:15
This is a fairly straightforward question that can be solved quickly by just applying the options

We are provided with Mean, m= 0
and T = {-2.22; -1.96; -1.68; 1.62; 1.94; 2.16} is the subset of S

T consists of all those elements in S that are more than 2 but less than 3 SDs away from the arithmetic mean of S

If an element is 1 SD away from the mean, we can write it as either m + SD or m - SD
Similarly, if an element is 2 SDs away from the mean, we can write it as either m + 2*SD or m - 2*SD

So, if these elements lie within 2 and 3 SDs of mean, m=0
we can find which one of these values of SD satisfies each value within T

Only SD = 0.77 does

Answer : B
Non-Human User
Joined: 09 Sep 2013
Posts: 9164
Re: The arithmetic mean of set S is zero. If T = {-2.22; -1.96; -1.68; 1.6  [#permalink]

Show Tags

22 Sep 2017, 08:43
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
Re: The arithmetic mean of set S is zero. If T = {-2.22; -1.96; -1.68; 1.6 &nbs [#permalink] 22 Sep 2017, 08:43
Display posts from previous: Sort by

The arithmetic mean of set S is zero. If T = {-2.22; -1.96; -1.68; 1.6

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics

 Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.
{"found_math": false, "script_math_tex": 0, "script_math_asciimath": 0, "math_annotations": 0, "math_alttext": 0, "mathml": 0, "mathjax_tag": 0, "mathjax_inline_tex": 0, "mathjax_display_tex": 0, "mathjax_asciimath": 0, "img_math": 0, "codecogs_latex": 0, "wp_latex": 0, "mimetex.cgi": 0, "/images/math/codecogs": 0, "mathtex.cgi": 0, "katex": 0, "math-container": 0, "wp-katex-eq": 0, "align": 0, "equation": 0, "x-ck12": 0, "texerror": 0}