Standard Deviation.

vinaynawani wrote:A certain characteristic in a large population has a distribution that is symmetric about the mean M. If 68 percent of the distribution lies within one standard deviation D of the mean, what percent of the distribution is less than M+D?

A. 16%
B.32%
C. 48%
D. 84%
E. 92%


Hey ppl.....dont know how to go about this 1.
Kindly Help.
Thanx.

isn't this question out of scope of GMAT... some instructor should intervene and suggest.

ohh...is it ???

i dont know.
Do let me know if thats d case...

vinaynawani wrote:ohh...is it ???

i dont know.
Do let me know if thats d case...

I think so but we will have to consult instructors.. wait for the reply of instructor ...btw what is the OS of the question...

The O.S. is D.

shashank.ism wrote:

vinaynawani wrote:A certain characteristic in a large population has a distribution that is symmetric about the mean M. If 68 percent of the distribution lies within one standard deviation D of the mean, what percent of the distribution is less than M+D?

A. 16%
B.32%
C. 48%
D. 84%
E. 92%


Hey ppl.....dont know how to go about this 1.
Kindly Help.
Thanx.

isn't this question out of scope of GMAT... some instructor should intervene and suggest.

shashank is true to certain extent. This one revolves ard a statistical rule called 34:14:2 concept( google it for more)

Yeah Answer will be 84%.

These are typical GRE based. Not GMAT ones....

gmatmachoman wrote:

shashank.ism wrote:

vinaynawani wrote:A certain characteristic in a large population has a distribution that is symmetric about the mean M. If 68 percent of the distribution lies within one standard deviation D of the mean, what percent of the distribution is less than M+D?

A. 16%
B.32%
C. 48%
D. 84%
E. 92%


Hey ppl.....dont know how to go about this 1.
Kindly Help.
Thanx.

isn't this question out of scope of GMAT... some instructor should intervene and suggest.

shashank is true to certain extent. This one revolves ard a statistical rule called 34:14:2 concept( google it for more)

Yeah Answer will be 84%.

These are typical GRE based. Not GMAT ones....

k
thanx.

vinaynawani wrote:

gmatmachoman wrote:

shashank.ism wrote:

vinaynawani wrote:A certain characteristic in a large population has a distribution that is symmetric about the mean M. If 68 percent of the distribution lies within one standard deviation D of the mean, what percent of the distribution is less than M+D?

A. 16%
B.32%
C. 48%
D. 84%
E. 92%


Hey ppl.....dont know how to go about this 1.
Kindly Help.
Thanx.

isn't this question out of scope of GMAT... some instructor should intervene and suggest.

shashank is true to certain extent. This one revolves ard a statistical rule called 34:14:2 concept( google it for more)

Yeah Answer will be 84%.

These are typical GRE based. Not GMAT ones....

k
thanx.

anyway, it's good to know the concepts.

The question says that

--------------------+--------------+------------+--------------------
____16% ___M-D__34%___M__34%__M+D___16%


given : 68% lies between M-D and M+D. So, values beyond (M+D) and (M-D) will constitute 32%, 16-16 distributed on both the sides as shown above.

So, there are 16+34+34 % values less than M+D.

HTH.