BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Median/Mean

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Junior | Next Rank: 30 Posts
Posts: 19
Joined: Fri Jul 16, 2010 1:27 am

Median/Mean

by RikaMueller » Sun Nov 28, 2010 2:08 am
A list of measurements in increasing order 4 5 6 8 10 and x. If the Median is 6/7 times their arithmetic mean. What is value of x?

16
15
14
13
12

Pls clarify. I chose 15 but this is wrong.
Top
Source: — Problem Solving |
User avatar
GMAT Instructor
Posts: 905
Joined: Sun Sep 12, 2010 1:38 am
Thanked: 378 times
Followed by:123 members
GMAT Score:760

by Geva@EconomistGMAT » Sun Nov 28, 2010 2:59 am
The median for an even number of terms is the average of the two middle terms. In this case, the median will equal the average of 6 and 8, or med=7.
If the median is 6/7*mean, then
7=6/7*mean

Mean is 49/6.

Since mean is "sum of terms" / number of terms", and number of terms is 6 (which corresponds to the bottom of 49/6, it follows that x must be a term that brings the sum to 49.

4+5+6+8+10+x=49
x=49-33 = 16.
Geva
Senior Instructor
Master GMAT
1-888-780-GMAT
https://www.mastergmat.com
Top
User avatar
Master | Next Rank: 500 Posts
Posts: 332
Joined: Tue Feb 09, 2010 3:50 pm
Thanked: 41 times
Followed by:7 members
GMAT Score:720

by rishab1988 » Sun Nov 28, 2010 4:03 am
This isn't a tough question.

The of terms including x are even.

The median = avg of 2 middle terms [6 and 8] = 7

Avg = (33+x)/6

Median = 6/7 Avg [ as per question]
7 * Median = 6* Avg
7*7 = 6 * (33+x)/6
49= 33+x
x=16

or A
Top
Post new topic Post Reply
• Page 1 of 1