GMAT PREP PS - MEAN and SD - The Beat The GMAT Forum - Expert GMAT Help & MBA Admissions Advice

If a certain sample of data has a mean of 20 and standard deviation of 3, which of the following values is more than 2.5 standard deviations from the mean?

a. 12
b. 13.5
c. 17
d. 23.5
e. 26.5

answer is a. 12

Can some one shed light on, how to get the answer?

Thanks.

Quote

satish.nagdev: Master | Next Rank: 500 Posts; Posts: 130; Joined: Sat Dec 29, 2007 5:35 am; Location: SGP; Thanked: 5 times

by satish.nagdev » Mon Nov 23, 2009 10:28 pm

clear explanation given here https://www.manhattangmat.com/forums/if- ... t4559.html

Thanks Ron Purewal

Wounded by GMAT but not dead

Quote

Post new topic Post Reply

• Page 1 of 1

5/5

5 Star (481 Reviews)

"Target Test Prep is the closest to the official version of the GMAT exam, about 99% accuracy in terms of the quality and quantity of information. The course has excellently created singular sets of focused lessons and tests for every possible topic that one could come across in the official GMAT exam."

"The TTP course maximizes the efficiency of the time you spend studying. It will take time and effort but I could almost guarantee that if you complete the course exactly as it is laid out you will get an amazing score. They also have a very responsive team willing to help with any questions you might have."

"TTP has two things that I think no other test prep company offers: A teaching approach that reinforces understanding and an attitude that will give you the mental preparedness needed to succeed on the test. TTP gives you a deep understanding of the concept you need to know while teaching you how to think."

Write a Review