Median problem from GMAT PREP. Plz help.

Expert replies

Previous Topic Next Topic

ok24by7: Junior | Next Rank: 30 Posts; Posts: 19; Joined: Thu Jul 17, 2008 9:05 pm; Thanked: 2 times

by ok24by7 » Sun Aug 31, 2008 10:26 am

How to solve this attached problem?
Attch added again..............

Thanks.

Attachments

New Microsoft Word Document.doc: (50.5 KiB) Downloaded 342 times

Last edited by ok24by7 on Sun Aug 31, 2008 10:40 am, edited 1 time in total.

Like this post

Source: Beat The GMAT — Problem Solving | Sun Aug 31, 2008 10:26 am

sudhir3127: Legendary Member; Posts: 829; Joined: Mon Jul 07, 2008 10:09 pmFollowed by: 3 members; Location: INDIA; Thanked: 84 times

Re: Median problem from GMAT PREP. Plz help.

by sudhir3127 » Sun Aug 31, 2008 10:30 am

ok24by7 wrote:How to solve this attached problem?

Thanks.

i dont see any attachment . did u forget to add the attachment?

Like this post

Mpalmer22: Newbie | Next Rank: 10 Posts; Posts: 7; Joined: Tue Aug 26, 2008 10:22 am

by Mpalmer22 » Fri Sep 05, 2008 1:09 pm

Think of the median as the middle number not as the average. The question is phrased difficultly in that it seems like it is telling you the median number is 73.

For example the median of this set of numbers:
1,2,3,4,4,4,4 is 4 b/c it is in the middle of the set.
However, if the set was:
1,2,3,4,4,4 is 3.5 b/c when you have an even number in the data set, you average the middle 2 numbers to get the median.

The problem you posted is a little tricky since it seems like the median would be closer to the average, but it is the middle number instead. I like to cross a numbers off of each end until if find the middle, and by doing that you see that the majority of the numbers are concentrated to the higher end.

Let me know if you need any more help on that.

Like this post

sg4931: Newbie | Next Rank: 10 Posts; Posts: 3; Joined: Thu Jul 24, 2008 2:35 pm

by sg4931 » Mon Sep 08, 2008 3:10 pm

There are 73 individual scores in total. Call them -- S1, S2,S3........S73.

Rewrite the score table as follows:
50 - 59 : S1, S2
60 - 69 : S3, S4,..,S12
70 - 79 : S13,S14,...S28
80 - 89 : S29, S30,...S37,...S55

The median score is S37 (37th score is the mid point of 73 scores)

Looking at the table above, 37th score falls in the 80 - 89 interval

This how i have understood it. A tricky question indeed!

Like this post

kaur21: Newbie | Next Rank: 10 Posts; Posts: 2; Joined: Tue Sep 09, 2008 7:30 am

by kaur21 » Tue Sep 09, 2008 9:22 am

Fundamentally, this question will be solved by calculating cumulative frequency.

Like this post

dally_gmat: Senior | Next Rank: 100 Posts; Posts: 31; Joined: Mon Sep 15, 2008 6:16 pm; Thanked: 3 times

by dally_gmat » Thu Sep 18, 2008 7:43 pm

I lay my cards on same explanation as given below..

sg4931 wrote:There are 73 individual scores in total. Call them -- S1, S2,S3........S73.

Rewrite the score table as follows:
50 - 59 : S1, S2
60 - 69 : S3, S4,..,S12
70 - 79 : S13,S14,...S28
80 - 89 : S29, S30,...S37,...S55

The median score is S37 (37th score is the mid point of 73 scores)

Looking at the table above, 37th score falls in the 80 - 89 interval

This how i have understood it. A tricky question indeed!

Like this post

robzoc: Senior | Next Rank: 100 Posts; Posts: 31; Joined: Tue Sep 16, 2008 8:29 am; Location: Brazil; GMAT Score:460

time

by robzoc » Tue Sep 23, 2008 8:38 am

some times ( like this one) i believe that it´s better to number all the scores like:

1 for 50-59
2 for 60-69
3 for 70-79
4 for 80-89
5 for 90-99

of course in the heat of the moment this will be something like (1,2,3,4,5)

112222222222333333333333333444444444444444444444444444444444444444444444555555555555555555555555

count 37 digits and you will find the right interval !

Like this post

artistocrat: Master | Next Rank: 500 Posts; Posts: 152; Joined: Wed Mar 12, 2008 4:36 pmFollowed by: 2 members; Thanked: 8 times

simplify

by artistocrat » Mon Oct 06, 2008 3:26 pm

Easiest solution. How many scores? 73. The median will be the 37th value. (36 below and 36 above). The 37th value is in the 4th score interval, 80-89.

Like this post

nicks: Newbie | Next Rank: 10 Posts; Posts: 4; Joined: Fri Sep 19, 2008 10:50 am

by nicks » Sun Oct 12, 2008 9:45 pm

How I solved it:

Add up total number of scores and divide by 2 (73/2 = 36.5)

Which one has the 36.5th number in it?

50-59 has numbers 1-2
60-69 has numbers 3-12
70-79 has numbers 13-28
80-89 has numbers 29-55
90-99 has numbers 56-73

29 < 36.5 < 55

Like this post

Post new topic Post Reply

• Page 1 of 1

GMAT Course Reviews

560 reviews

1168 reviews

431 reviews

359 reviews

147 reviews

5/5

5 Star (560 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