sorry, i just posted in PB forum..
DS question with median .. ??
What is the median number of employee assigned per project for the projects at company z?
1) 25% of the project at company Z have 4 or more employees assigned to each project.
2) 35% of the project at company z have 2 or fewer employee assigned to each project
pls help, many thanks.
answer is C
median question..
-
- Senior | Next Rank: 100 Posts
- Posts: 41
- Joined: Thu Jul 12, 2007 1:16 am
- Location: Cape Town South Africa
- Thanked: 5 times
Good question - please comment on my logic
35% is less or equal to 2 and 25% is greater or equal to 4. Thus 40% is equal to 3.
So if it is a even number of projects the median will be (3+3)/2 or if it's odd, the answer will be simply 3.
35% is less or equal to 2 and 25% is greater or equal to 4. Thus 40% is equal to 3.
So if it is a even number of projects the median will be (3+3)/2 or if it's odd, the answer will be simply 3.
- Stuart@KaplanGMAT
- GMAT Instructor
- Posts: 3225
- Joined: Tue Jan 08, 2008 2:40 pm
- Location: Toronto
- Thanked: 1710 times
- Followed by:614 members
- GMAT Score:800
Good logic and right answer!Saffa wrote:Good question - please comment on my logic
35% is less or equal to 2 and 25% is greater or equal to 4. Thus 40% is equal to 3.
So if it is a even number of projects the median will be (3+3)/2 or if it's odd, the answer will be simply 3.
Statement (1) by itself is insufficient because we have no clue how the rest of the employees are assigned... same problem with statement (2).
When we combine the statement, we know that all the other projects have 3 employees assigned to each of them. If we were to write out the list, "3" would cover the middle terms, so it will end up being the median of the set.
Stuart Kovinsky | Kaplan GMAT Faculty | Toronto
Kaplan Exclusive: The Official Test Day Experience | Ready to Take a Free Practice Test? | Kaplan/Beat the GMAT Member Discount
BTG100 for $100 off a full course
- Stuart@KaplanGMAT
- GMAT Instructor
- Posts: 3225
- Joined: Tue Jan 08, 2008 2:40 pm
- Location: Toronto
- Thanked: 1710 times
- Followed by:614 members
- GMAT Score:800
(1) 25% of the project at company Z have 4 or more employees assigned to each project.Thephu wrote:I don't understand why do you know that 40% is 3.
Can you please explain more..
many thanks
(2) 35% of the project at company z have 2 or fewer employee assigned to each project
Statement (1) covers all of the cases where there are 4 or more employees per project. Statement (2) covers all of the cases where there are 2 or fewer employees per project. The only possible # of employees per project that hasn't been covered is exactly 3, which must account for all the remaining scenarios.
So, 100% - (25% + 35%) = 40% for exactly 3 employees/project.
Stuart Kovinsky | Kaplan GMAT Faculty | Toronto
Kaplan Exclusive: The Official Test Day Experience | Ready to Take a Free Practice Test? | Kaplan/Beat the GMAT Member Discount
BTG100 for $100 off a full course
-
- Legendary Member
- Posts: 1161
- Joined: Mon May 12, 2008 2:52 am
- Location: Sydney
- Thanked: 23 times
- Followed by:1 members
Sorry for opening an old thread !!
I understand the first part but how are we adding up 3 + 3 / 2 in the case of even number of projects.
I am not able to understand how do we get 3 + 3?
I understand the first part but how are we adding up 3 + 3 / 2 in the case of even number of projects.
I am not able to understand how do we get 3 + 3?
Stuart Kovinsky wrote:Good logic and right answer!Saffa wrote:Good question - please comment on my logic
35% is less or equal to 2 and 25% is greater or equal to 4. Thus 40% is equal to 3.
So if it is a even number of projects the median will be (3+3)/2 or if it's odd, the answer will be simply 3.
Statement (1) by itself is insufficient because we have no clue how the rest of the employees are assigned... same problem with statement (2).
When we combine the statement, we know that all the other projects have 3 employees assigned to each of them. If we were to write out the list, "3" would cover the middle terms, so it will end up being the median of the set.
- Stuart@KaplanGMAT
- GMAT Instructor
- Posts: 3225
- Joined: Tue Jan 08, 2008 2:40 pm
- Location: Toronto
- Thanked: 1710 times
- Followed by:614 members
- GMAT Score:800
When there are an even number of terms in a set, the median is the average (mean) of the two middle terms.mehravikas wrote:Sorry for opening an old thread !!
I understand the first part but how are we adding up 3 + 3 / 2 in the case of even number of projects.
I am not able to understand how do we get 3 + 3?
We know that the first 35% of the projects have 2 members, the middle 40% of the projects have 3 members and the top 25% of the projects have 4 members. If we think about it in a row:
1%-----2 members-----35%36%------------3 members-----------75%76%--------4 members--------100%
we can see that the projects on either side of the 50% mark will both have 3 members in them.
So, we use the average formula:
Avg = sum of terms / # of terms = (3+3)/2 = 3
giving us our median of 3.
Stuart Kovinsky | Kaplan GMAT Faculty | Toronto
Kaplan Exclusive: The Official Test Day Experience | Ready to Take a Free Practice Test? | Kaplan/Beat the GMAT Member Discount
BTG100 for $100 off a full course
-
- Legendary Member
- Posts: 610
- Joined: Fri Jan 15, 2010 12:33 am
- Thanked: 47 times
- Followed by:2 members
(1) 25% of the project at company Z have 4 or more employees assigned to each project.
(2) 35% of the project at company z have 2 or fewer employee assigned to each project
hence 40% have exactly 3 employeees , so can we say safely that bulk of projects involve 3 employees. Hence the Median is 3.
Hope the logic is correct ?[/url]
(2) 35% of the project at company z have 2 or fewer employee assigned to each project
hence 40% have exactly 3 employeees , so can we say safely that bulk of projects involve 3 employees. Hence the Median is 3.
Hope the logic is correct ?[/url]
- skprocks
- Senior | Next Rank: 100 Posts
- Posts: 44
- Joined: Sun Dec 27, 2009 8:50 am
- Thanked: 3 times
- GMAT Score:710
The remaining 40% of projects have 3 ppl,why? It can be possible that they have 10ppl.
Please explain me.
I understand that the least 25% are <=2
Max 35% are >=4
Then the rest 40% could also be <=2 or >=4 or 3.Am I correct?
Please Clarify.
Please explain me.
I understand that the least 25% are <=2
Max 35% are >=4
Then the rest 40% could also be <=2 or >=4 or 3.Am I correct?
Please Clarify.
- sumanr84
- Legendary Member
- Posts: 758
- Joined: Sat Aug 29, 2009 9:32 pm
- Location: Bangalore,India
- Thanked: 67 times
- Followed by:2 members
25% are <=2 that means it could have 0,1 or 2 number of employees/ projectskprocks wrote:The remaining 40% of projects have 3 ppl,why? It can be possible that they have 10ppl.
Please explain me.
I understand that the least 25% are <=2
Max 35% are >=4
Then the rest 40% could also be <=2 or >=4 or 3.Am I correct?
Please Clarify.
Max 35% are >=4 that means it could have 4,5,6,......any number(we don't know) per project
rest 40% could also be <=2 or >=4 or 3.Am I correct?
No, Since the range <=2 and >=4 is already covered with above scenario. So, we are left with only one possibility i.e. 3 employee/project.
I am on a break !!
Hi,
I'm so sorry, but I just don't get it!
I wanted to open a new thread for this question but searched and found this one.
I understand that 40% of the projects will have 3 employees.
35% have 2 or less : ok.
But what bothers me is the 25% that have 4 or more. It could be any number above 4...
So how could we say that median is 3 ?
Of course 40>25 and 40>35 but that doesn't mean the median will be the number of employees in the 40% (3)!
Help please!
I'm so sorry, but I just don't get it!
I wanted to open a new thread for this question but searched and found this one.
I understand that 40% of the projects will have 3 employees.
35% have 2 or less : ok.
But what bothers me is the 25% that have 4 or more. It could be any number above 4...
So how could we say that median is 3 ?
Of course 40>25 and 40>35 but that doesn't mean the median will be the number of employees in the 40% (3)!
Help please!
- Stuart@KaplanGMAT
- GMAT Instructor
- Posts: 3225
- Joined: Tue Jan 08, 2008 2:40 pm
- Location: Toronto
- Thanked: 1710 times
- Followed by:614 members
- GMAT Score:800
You may be confusing median with arithmetic mean.bowen380 wrote:Hi,
I'm so sorry, but I just don't get it!
I wanted to open a new thread for this question but searched and found this one.
I understand that 40% of the projects will have 3 employees.
35% have 2 or less : ok.
But what bothers me is the 25% that have 4 or more. It could be any number above 4...
So how could we say that median is 3 ?
Of course 40>25 and 40>35 but that doesn't mean the median will be the number of employees in the 40% (3)!
Help please!
The median is the middle term of an ordered set. The values of the other terms is irrelevant when calculating the median.
For example:
{2, 2, 2, 2, 3, 3, 3, 3, 3, 4, 4, 4, 4}
and
{2, 2, 2, 2, 3, 3, 3, 3, 3, 100, 1000, 10000, 100000}
both have medians of 3.
* * *
(As a small aside: if there's an odd number of terms, the median is the middle term; if there's an even number of terms, the median is the arithmetic mean of the two middle terms.)
Stuart Kovinsky | Kaplan GMAT Faculty | Toronto
Kaplan Exclusive: The Official Test Day Experience | Ready to Take a Free Practice Test? | Kaplan/Beat the GMAT Member Discount
BTG100 for $100 off a full course