It is currently 18 Nov 2017, 18:43

### 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

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 June
Open Detailed Calendar

# Standard Deviation-Gmat prep

Author Message
Senior Manager
Joined: 23 May 2008
Posts: 414

Kudos [?]: 468 [0], given: 14

### Show Tags

10 Dec 2009, 12:27
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 1 sessions

### HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

Need to know the approach to solve such questions.

Attachments

SD.jpg [ 80.52 KiB | Viewed 1207 times ]

Kudos [?]: 468 [0], given: 14

Senior Manager
Affiliations: PMP
Joined: 13 Oct 2009
Posts: 296

Kudos [?]: 175 [4], given: 37

### Show Tags

10 Dec 2009, 12:40
4
KUDOS
let m be mean and d be sd

we are given
m-2d = 58
m+3d=98

solving these we get m=74,d=8

some questions give elements of set (sometimes give mean and sd also) and ask how many are 1sd above mean or how many are 2sd below mean etc., questions.
u can answer such questions too with similar approach as for the question u posted
_________________

Thanks, Sri
-------------------------------
keep uppp...ing the tempo...

Press +1 Kudos, if you think my post gave u a tiny tip

Kudos [?]: 175 [4], given: 37

Senior Manager
Joined: 25 Jun 2009
Posts: 289

Kudos [?]: 227 [0], given: 4

### Show Tags

14 Dec 2009, 09:36
Another way is to note that there are 5 deviations between 98 and 58, and 98-58=40, so 40/5 equalts 8. 58 + 2(8)= 74 or 98-3(8)=74

Kudos [?]: 227 [0], given: 4

Re: Standard Deviation-Gmat prep   [#permalink] 14 Dec 2009, 09:36
Display posts from previous: Sort by