Events & Promotions
|
|
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
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Jun 0408:30 AM PDT
-09:30 AM PDT
For most test takers, Data Insights is the most challenging section on the GMAT, with test takers scoring several points lower on average on DI than on Quant or Verbal and completing the section with less time to spare.
May 2910:00 AM IST
-11:00 PM IST
Start your journey with a fully customized action plan and work with a dedicated mentor to achieve a 735+ score.- Jun 03
08:30 AM PDT
-09:30 AM PDT
In Episode 7 of our GMAT Ninja CR series, we are rounding up the oddballs, the misfits, and the format-benders: EXCEPT, Fill-In-The-Blanks, and other unusual Critical Reasoning question types. When you see a question that ends with a literal blank line - Jun 10
06:00 AM PDT
-06:15 PM PDT
Register for the GMAT Club Virtual MBA Spotlight Fair – the world’s premier event for serious MBA candidates. This is your chance to hear directly from Admissions Directors at nearly every Top 30 MBA program..
16 Nov 2010, 23:37
Kudos
Bookmarks
I was using the Quant notes by "Target" and I came to this explanation:
Normal distribution follows the pattern: 2%, 14%, 34%, mean, 34%, 14%, 2%. Where to use:
Princeton Review Math Bin4, Q3. if question says mean of normal distribution is 72 and we can find
that 2% people are above 82. this means that 82 which is 2 standard deviations away (since 2% is
two steps away form mean,34% then 14%), thus one standard deviation is 82-72=10/2 = 5. Now
bottom 16% will be one standard deviation away from mean (left side, 2% +14%=16%) therefore, 72-
5=67.
I understand the basic principle of standard deviation, of how far numbers are from the mean, creating a bell curve distribution. However, to me this says if 72 is the mean and 1 standard deviation is 5, then 72(mean) 77(34) 82(14) 87(2%)... I know I am missing something so can someone please explain to me the distribution patter within this set of numbers? Thank you ahead of time.
Normal distribution follows the pattern: 2%, 14%, 34%, mean, 34%, 14%, 2%. Where to use:
Princeton Review Math Bin4, Q3. if question says mean of normal distribution is 72 and we can find
that 2% people are above 82. this means that 82 which is 2 standard deviations away (since 2% is
two steps away form mean,34% then 14%), thus one standard deviation is 82-72=10/2 = 5. Now
bottom 16% will be one standard deviation away from mean (left side, 2% +14%=16%) therefore, 72-
5=67.
I understand the basic principle of standard deviation, of how far numbers are from the mean, creating a bell curve distribution. However, to me this says if 72 is the mean and 1 standard deviation is 5, then 72(mean) 77(34) 82(14) 87(2%)... I know I am missing something so can someone please explain to me the distribution patter within this set of numbers? Thank you ahead of time.
Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Quantitative Questions Forum
Still interested in this question? Check out the "Best Topics" block below for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
19 Nov 2010, 11:12
Kudos
Bookmarks
mmcooley33
Let me start by saying that it is incredibly unlikely that you will EVER need to know this much detail about standard deviation on the GMAT. In my 20+ years of GMAT teaching experience, I have never seen nor heard of a real GMAT question that required you to know anything about a normal distribution.
That said, the concept with which your struggling is something that could come up in other contexts, so it's worth addressing the issue.
You've misinterpreted the original information slightly, which is why you're confused. Let's start with 1 SD from the mean.
In a normal distribution, 68% (34% + 34%) of data points are within 1 SD of the mean, "within" being the key word. So, in the example given, 68% of the numbers will be in the range 67 < x < 77.
Similarly, 68 + 28 = 96% of data points will be within 2 SDs of the mean. So, 96% of the numbers will be in the range 62 < x < 82.
We have 4% of the population remaining, so 2% will be less than 62 and 2% will be greater than 82.
Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Quantitative Questions Forum
Still interested in this question? Check out the "Best Topics" block above for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
