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.
Apr 1612:00 PM EDT
-11:59 PM EDT
You’re first to know: Save $200 on GMAT prep starting tomorrow, 4/13. Get 6 official practice tests and study with real questions. Be ready to save!
Apr 2610:00 AM EDT
-11:00 AM EDT
The Target Test Prep course represents a quantum leap forward in GMAT preparation, a radical reinterpretation of the way that students should study. Try before you buy with a 5-day, full-access trial of the course for FREE!
Apr 2711:00 AM EDT
-12:00 PM EDT
Prefer video-based learning? The Target Test Prep OnDemand course is a one-of-a-kind video masterclass featuring 400 hours of lecture-style teaching by Scott Woodbury-Stewart, founder of Target Test Prep and one of the most accomplished GMAT instructors
Apr 2808:00 AM PDT
-11:00 AM PDT
Whether you are just beginning your MBA journey or fine-tuning your path to a 700+ score, GMAT Day is designed to give you a competitive edge.
08 Sep 2007, 13:14
Kudos
Bookmarks
E
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
5%
(low)
Question Stats:
84% (00:53) correct
16%
(00:52)
wrong
based on 463
sessions
History
Date
Time
Result
Not Attempted Yet
Is the standard deviation of the salaries of Company Y’s employees greater than the standard deviation of the salaries of Company Z’s employees?
(1) The average (arithmetic mean) salary of Company Y’s employees is greater than the average salary of Company Z’s employees.
(2) The median salary of Company Y’s employees is greater than the median salary of Company Z’s employees.
(1) The average (arithmetic mean) salary of Company Y’s employees is greater than the average salary of Company Z’s employees.
(2) The median salary of Company Y’s employees is greater than the median salary of Company Z’s employees.
11 Sep 2010, 23:33
Kudos
Bookmarks
gluon
This one is straight E. No need to look for examples.
"Standard deviation shows how much variation there is from the mean. A low standard deviation indicates that the data points tend to be very close to the mean, whereas high standard deviation indicates that the data are spread out over a large range of values."
We know only that mean(Y)>mean(Z) and median(Y)>median(Z) - absolutely useless info to compare SD's.
But still if you need an example:
Consider company Y to have one employee with a salary of $10, so SD(Y)=0 (if Range or SD of a list is 0, then the list will contain all identical elements. And vise versa: if a list contains all identical elements then the range and SD of a list is 0. If the list contains 1 element: Range is zero and SD is zero) and company Z to have two employees with a salaries of $1 and $2, so SD(Z)>0: mean(Y)>mean(Z) and median(Y)>median(Z) but SD(Z)>SD(Y)=0;
Now, consider company Y to have two employees with a salaries of $10 and $11, so SD(Y)>0 and company Z to have one employee with a salary of $1, so SD(Z)=0: mean(Y)>mean(Z) and median(Y)>median(Z) but SD(Y)>SD(Z)=0.
For more on standard deviation check:
SD chapter of Math Book: math-standard-deviation-87905.html
PS questions on SD: ps-questions-about-standard-deviation-85897.html
DS questions on SD: ds-questions-about-standard-deviation-85896.html
Hope it helps.
General Discussion
08 Sep 2007, 14:34
Kudos
Bookmarks
gluon
Straight E
(1) say y = {3,3,3}, z = {1,1,1)
Same SD, but Avg(y) > Avg(z)
say y = {1,3,5}, z = {1,1,1)
Different SD, but Avg(y) > Avg(z)
INSUFFICIENT
(2) Using the same case above, INSUFFICIENT
Together, still same case.
