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

Redeem

Percentile

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Legendary Member
Posts: 559
Joined: Tue Mar 27, 2007 1:29 am
Thanked: 5 times
Followed by:2 members

Percentile

by Cybermusings » Sun Apr 29, 2007 4:04 am
Amy's grade was the 90th percentile of the 80 grades in her class. Of the grades from another class, 19 people were above Amy and the rest all below her. If no other grade was the same as Amy's grade, then Amy was what percentile of the grades of the 2 classes combines

1) 72nd
2) 80th
3) 81st
4) 85th
5) 92nd

Juvenile question - Please help me out with calculations! Are there any formulas that we can adhere to?
Top
Source: — Problem Solving |
User avatar
Community Manager
Posts: 789
Joined: Sun Jan 28, 2007 3:51 pm
Location: Silicon valley, California
Thanked: 30 times
Followed by:1 members

Re: Percentile

by jayhawk2001 » Sun Apr 29, 2007 8:35 am
Cybermusings wrote:Amy's grade was the 90th percentile of the 80 grades in her class. Of the grades from another class, 19 people were above Amy and the rest all below her. If no other grade was the same as Amy's grade, then Amy was what percentile of the grades of the 2 classes combines

1) 72nd
2) 80th
3) 81st
4) 85th
5) 92nd

Juvenile question - Please help me out with calculations! Are there any formulas that we can adhere to?
10% out of 80 grades are higher than Amy i.e. 8 grades
From the other class 19 people scored above Amy

So, total of 19+8 = 27 grades are higher than Amy's

Amy's combined percentile = 100 - 27/(80 + x)

Where x is the total number of grades in the other class. The
question does not mention the total number of grades in the other
class.
Top
Legendary Member
Posts: 559
Joined: Tue Mar 27, 2007 1:29 am
Thanked: 5 times
Followed by:2 members

by Cybermusings » Mon Apr 30, 2007 1:18 am
Oops sorry...there are a total of 100 grades in the other class...Sorry about the omission...Can you help me with percentile calculations...using some examples!



The OA btw is 85
Top
Newbie | Next Rank: 10 Posts
Posts: 5
Joined: Mon Apr 30, 2007 7:14 am

by goutamn » Mon Apr 30, 2007 8:29 am
In the 1st class 10% of the class is above Amy, ie 8
& in the 2nd class 19 of 100 are above Amy. Both classes
combined 27 ppl are above Amy. % above Amy in both classes
combined is 27/180 = 15 % That slots Amy in the (100-1) = 85th percentile
Top
User avatar
Community Manager
Posts: 789
Joined: Sun Jan 28, 2007 3:51 pm
Location: Silicon valley, California
Thanked: 30 times
Followed by:1 members

by jayhawk2001 » Mon Apr 30, 2007 9:00 pm
Cybermusings wrote:Oops sorry...there are a total of 100 grades in the other class...Sorry about the omission...Can you help me with percentile calculations...using some examples!



The OA btw is 85
Assume there are 5 people in a class and they get the following scores
out of 100.

60 70 80 90 100

The person getting 90 has a "percentage" score of 90. But only 1
person has a higher score than him. So, he falls in the upper 1 / 5
of the class. Translating this to percentile, (1 - 1/5)*100 = 80 percentile
i.e. 80% of the class is below what he has scored.

Using this for the question in hand,

Total of 19+8 = 27 grades are higher than Amy's

Amy's combined percentile = 1 - 27/(80 + 100) = 85 percentile
Top

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 8087
Joined: Sat Apr 25, 2015 10:56 am
Location: Los Angeles, CA
Thanked: 43 times
Followed by:29 members

by Scott@TargetTestPrep » Mon May 20, 2019 6:14 pm
Cybermusings wrote:Amy's grade was the 90th percentile of the 80 grades in her class. Of the grades from another class, 19 people were above Amy and the rest all below her. If no other grade was the same as Amy's grade, then Amy was what percentile of the grades of the 2 classes combines

1) 72nd
2) 80th
3) 81st
4) 85th
5) 92nd
Since Amy's grade is in the 90th percentile of the 80 grades in her class, 10% of the number of total grades in her class are not lower than Amy's grade; i.e., 8 grades. Note that these 8 grades include Amy's own grade. When combined with the number of grades from the other class, there are 8 + 19 = 27 grades that are not lower than Amy's grade, including Amy's own, in a total of 80 + 100 = 180 grades. Since 27 / 180 = 0.15, this amounts to 15% of all the grades. Therefore, Amy's grade is the 100 - 15 = 85th percentile of the combined grades of the two classes.

Answer: D

Scott Woodbury-Stewart
Founder and CEO
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

ImageImage
Top
Post new topic Post Reply
• Page 1 of 1