首页 | 学习中心 | 注册 登录
返回列表 发帖
lunarfollies

Rank: 2

UID
223364 
帖子
239 
主题
47 
注册时间
2011-7-11 
最后登录
2014-7-31 
1# 跳转到 » 倒序看帖
打印
tT
发表于 2013-4-8 22:33 | 只看该作者

Qbank id 1745 mistake?

following, question, solution, believe, mistake
Hello Guys
I believe there is a mistake in question id 1745.
Problem: What are the median and the third quintile of the following data points?
9.2% 10.1% 11.5% 11.9% 12.2% 12.8% 13.1% 13.6% 13.9% 14.2% 14.8% 14.9% 15.4%
Qbank solution is 13.1% median and third quintile is 13.7%
Qbank interpolation is: 0.136 + (o.4)(0.1390.136)= o.1372 =>13.7%
My solution is: 0.136 + (0.6 due to third quintile)(0.1390.136) = 0.1378 =13.8%, but not given as one of the solution options.
third quintile is 0.6.

Feedback welcomed
收藏 分享

dcfox83

Rank: 2

UID
223264 
帖子
251 
主题
127 
注册时间
2011-7-11 
最后登录
2016-4-19 
2#
发表于 2013-4-8 22:33 | 只看该作者
I would have thought it to be 13.7 as well. Arriving this way:
(n+1)(3/5) = (13+1)*3/5 = 8.4
8th is .136
0.4th is (0.4)(0.1390.136)
I think you are trying to use 0.6 directly in the linear interpolation.

TOP

eoin

Rank: 2

UID
223396 
帖子
309 
主题
9 
注册时间
2011-7-11 
最后登录
2016-4-19 
3#
发表于 2013-4-8 22:33 | 只看该作者
For finding the solution, You are rite, median is 13.1%.
Now,
For finding quintile,
it is Ly= ((n+1)*y)/100;
so here y=75%.
It is coming out as 10.6
so it will be,
14.2+ 0.6*(14.814.2)=14.56.
So third quantile will be 14.56.

TOP

Iginla2011

Rank: 2

UID
222302 
帖子
408 
主题
11 
注册时间
2011-7-2 
最后登录
2016-6-23 
4#
发表于 2013-4-8 22:34 | 只看该作者
Yes no doubt…but why are you using 0.4 in the interpolation instead 0.6?
I used 0.6 because 3/5 = 0.6
How are you getting 0.4 to calculate L?

TOP

former

UID
222293 
帖子
680 
主题
67 
注册时间
2011-7-2 
最后登录
2016-4-19 
5#
发表于 2013-4-8 22:34 | 只看该作者
Prasenjith your way is right, but y = 60% in this question and not 75% ;) But you used just like I did 0.6 as y. y =0.6
Thanks for all the replies

TOP

Houjichasan

Rank: 2

UID
223419 
帖子
295 
主题
13 
注册时间
2011-7-11 
最后登录
2014-8-7 
6#
发表于 2013-4-8 22:35 | 只看该作者
I am using 0.4 because I arrived at 8.4 ; that is the 0.4 fractions from the 8th to 9th element.
When calculating 8.4, you have already used the 3/5 logic.

TOP

FVPV

Rank: 2

UID
223262 
帖子
239 
主题
117 
注册时间
2011-7-11 
最后登录
2016-4-18 
7#
发表于 2013-4-8 22:35 | 只看该作者
Yes Guys, I did a mistake….I thought it to be 1/4 th part….I have not seen as quintile…sorry…it will be 60%( 100*3/5)…
And then ratio will be
Ly= (14*(60))/100
=8.4( hope I pressed calculator accurately)
In that case it will be
=13.6+0.4(13.913.6)
=13.72 (hope I pressed calculator accurately
Thanks a lot

TOP

d2rockstar

Rank: 2

UID
223341 
帖子
249 
主题
31 
注册时间
2011-7-11 
最后登录
2013-8-23 
8#
发表于 2013-4-8 22:35 | 只看该作者
Ok thank you very much you both. I understand it now. the 0.4 is taken from the 8.4 and used for the interpolation and not the 60% ;).
13.72 is correct!
Once again thanks for the help.

TOP

返回列表