Last visit was: 21 Nov 2024, 07:45 It is currently 21 Nov 2024, 07:45

Close

GRE Prep 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

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GRE score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel
SORT BY:
Date
avatar
Senior Manager
Senior Manager
Joined: 20 May 2014
Posts: 285
Own Kudos [?]: 702 [6]
Given Kudos: 225
avatar
Director
Director
Joined: 03 Sep 2017
Posts: 518
Own Kudos [?]: 703 [2]
Given Kudos: 0
Send PM
avatar
Intern
Intern
Joined: 23 Nov 2017
Posts: 45
Own Kudos [?]: 87 [0]
Given Kudos: 0
Send PM
avatar
Intern
Intern
Joined: 20 Feb 2020
Posts: 5
Own Kudos [?]: 2 [0]
Given Kudos: 0
Send PM
Re: In a survey, 86 high school students were randomly selected [#permalink]
Eidolons03 wrote:
If I had gotten this one wrong, I probably would have given up my plans to become a statistician!!!!!!!

The median is basically the number in a set that is right in the middle of the set. In order to find the median, you first need to WRITE THE NUMBERS IN A SET IN ASCENDING ORDER.

3 - 5 - 6 - 7 - 13 - 17 - 35

Now we need to look at the set and decide which number is in the middle. 7 is the best choice because there are exacltly 3 numbers to its right (13, 17 and 35) and 3 numbers to its left (3.5 and 6).

Qunatity B is thus 7.

The mean is the avarage of all numbers in a set. All we need to do is add all numbers together and divide the result by how many numbeers there are in the set.

3 + 5 + 6 + 7 + 13 + 17 + 35 = 86

There are 7 numbers in this set.

86/7 = 12.3

Quantity A is 12.3

Qunaity A is greater than quantity B. A is the answer.

This histogram can be a bit tricky to read so I may have gotten some of the numbers wrong.


Why are you using the set of students 3 - 5 - 6 - 7 - 13 - 17 - 35 not the set of hours ?
Verbal Expert
Joined: 18 Apr 2015
Posts: 29999
Own Kudos [?]: 36332 [0]
Given Kudos: 25923
Send PM
Re: In a survey, 86 high school students were randomly selected [#permalink]
Expert Reply
Yes you are right. To answer that question must be used the values on the x axis and NOT those on the y axis

Regards
avatar
Intern
Intern
Joined: 19 Feb 2020
Posts: 28
Own Kudos [?]: 1 [0]
Given Kudos: 0
Send PM
Re: In a survey, 86 high school students were randomly selected [#permalink]
Thank you
avatar
Intern
Intern
Joined: 25 Apr 2020
Posts: 13
Own Kudos [?]: 3 [0]
Given Kudos: 0
Send PM
Re: In a survey, 86 high school students were randomly selected [#permalink]
I am not able to understand how the set 3 - 5 - 6 - 7 - 13 - 17 - 35 has been derived. Please help me here. I am Lost in the tricky histogram details.
Intern
Intern
Joined: 30 Nov 2020
Posts: 26
Own Kudos [?]: 4 [0]
Given Kudos: 14
Send PM
Re: In a survey, 86 high school students were randomly selected [#permalink]
Can someone please help with the question above?
Verbal Expert
Joined: 18 Apr 2015
Posts: 29999
Own Kudos [?]: 36332 [1]
Given Kudos: 25923
Send PM
Re: In a survey, 86 high school students were randomly selected [#permalink]
1
Expert Reply
On trick is that the median always follow the tail and the tail goes down

The Mean must be higher than the median

A is the answer


Attachment:
newest-histogram (1).jpg
newest-histogram (1).jpg [ 46.08 KiB | Viewed 9244 times ]
Manager
Manager
Joined: 11 Jun 2023
Posts: 77
Own Kudos [?]: 77 [3]
Given Kudos: 14
Send PM
Re: In a survey, 86 high school students were randomly selected [#permalink]
1
2
Bookmarks
Here is how I solved it:
First compute the median, since that is the easiest. Since there are 86 values, the median will be the average of the 43rd and 44th value, which is contained in the set "6-10". Therefore, the median can be at least 6 and at most 10.

Now compute the minimum of the mean - by taking the lowest of each set.
The calculation is as follows: (1*14)+(35*6)+(16*11)+(16*5)+(5*21)+(4*26)+(7*31)=906
89 times 10 is 890, so if the sum is 906 - then that implies that the average is at least 10.something, which is greater than the highest value of our median (10).

Note that the above method is not great - you have to estimate the the number of people, and it is likely not very precise (for example you could estimate a value wrong and get something like 890). It is far better to remember how median and mean are affected by distribution, which would lead you to the correct solution in 20 seconds.
Moderators:
GRE Instructor
83 posts
GRE Forum Moderator
37 posts
Moderator
1111 posts
GRE Instructor
234 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne