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Curve calculation help

Posted: Wed Jan 20, 2010 1:56 pm
by orov
I bombed at BC/BU/Fordham/GW this semester. I have a 2.886 (b+ and 2 b-'s)

median is a 3.316 and top 10 is 3.643. any way to figure out about where i am?

I know i'm most likely bottom 10, i'd just like to know what the math says

Re: Curve calculation help

Posted: Wed Jan 20, 2010 2:03 pm
by AtticusFinch
The math says 2.989 is bottom 10 percent. Sorry math doesn't lie.

Re: Curve calculation help

Posted: Wed Jan 20, 2010 2:09 pm
by Grad_Student
Man I dunno whats better, my schools median is like 2.5

Re: Curve calculation help

Posted: Wed Jan 20, 2010 2:11 pm
by thesealocust
nm

Re: Curve calculation help

Posted: Wed Jan 20, 2010 2:13 pm
by RVP11
thesealocust wrote:
orov wrote:I bombed at BC/BU/Fordham/GW this semester. I have a 2.886 (b+ and 2 b-'s)

median is a 3.316 and top 10 is 3.643. any way to figure out about where i am?

I know I'm most likely bottom 10, i'd just like to know what the math says
Math here, always happy to help:

Median = 3.316. Top 10% is .327 more than that.

(Standard deviation) (z-score for top 10%) = .327

SD = .327 / 1.28 = 0.255

3.316 - 2.886 = .43, .43 / 0.255 = 1.68 standard deviations below the mean.

That is roughly speaking bottom 5%
Have you done this for UVA? I know 3.3 = median, 3.4 = about top 33%, 3.5 = about top 25%, and 3.7 = top 7%, but I'd be curious to know the 10%, 20%, 30%, 40%, etc.

Re: Curve calculation help

Posted: Wed Jan 20, 2010 2:16 pm
by OperaSoprano
thesealocust wrote:
orov wrote:I bombed at BC/BU/Fordham/GW this semester. I have a 2.886 (b+ and 2 b-'s)

median is a 3.316 and top 10 is 3.643. any way to figure out about where i am?

I know I'm most likely bottom 10, i'd just like to know what the math says
Math here, always happy to help:

Median = 3.316. Top 10% is .327 more than that.

(Standard deviation) (z-score for top 10%) = .327

SD = .327 / 1.28 = 0.255

3.316 - 2.886 = .43, .43 / 0.255 = 1.68 standard deviations below the mean.

That is roughly speaking bottom 5%
You! The use of math is disallowed for telling people things like that.

Re: Curve calculation help

Posted: Wed Jan 20, 2010 2:18 pm
by thesealocust
nm

Re: Curve calculation help

Posted: Wed Jan 20, 2010 5:13 pm
by Alyosha
Paging Thesealocust or Rayiner (or whoever can help)!

Last year's numbers were (this is for the current 2Ls after their 1st year):

top 10%: 3.76

Top 33%: 3.50

top 50%: 3.29.

Is there anyway to figure out the cutoff for top 25% and top 5%? My school's website says we curve to a 3.2 or 3.3, and that:
35% get A or A-
55% get B+, B, or B-
10% get anything less. but there is an acceptable 4% change in either direction for each category (A's could be 31% or 39% for example).

There is also a required mean requirement of 3.25, with a range of 3.2 to 3.3 permitted. Thanks for any help.

Re: Curve calculation help

Posted: Wed Jan 20, 2010 5:51 pm
by thesealocust
nm

Re: Curve calculation help

Posted: Wed Jan 20, 2010 6:02 pm
by Alyosha
No, UNC. I agree the numbers are huge, all the A's must go to the same people. Thanks a lot sealocust!

Re: Curve calculation help

Posted: Wed Jan 20, 2010 7:44 pm
by jp0094
Some help would be appreciated! This one is a bit trickier.

The old curve was 2.85 and came out like this

Top 10%: 3.54
Top 25%: 3.29
Top 33%: 3.23
Top 50%: 3.07
Top 75%: 2.77

The curve is now 3.05. Where does a 3.5 gpa land me?

Re: Curve calculation help

Posted: Wed Jan 20, 2010 7:49 pm
by kareenak888
simple plug and chug. Has no one learned about the z statistics?

Re: Curve calculation help

Posted: Wed Jan 20, 2010 8:37 pm
by YCrevolution
..

Re: Curve calculation help

Posted: Wed Jan 20, 2010 8:43 pm
by rayiner
Depending on your school (eg: NU) your curve may not be normally distributed. For most schools, the upper tail is very spread out and the lower tail is very bunched-up.

Re: Curve calculation help

Posted: Wed Jan 20, 2010 9:30 pm
by mynameiswhat
is there any way to figure out how gpa correlates to rank if the rank is unpublished until after graduation?

all i have is the target median for curved classes, which is 3.19 (this is for michigan). and i haven't been able to find another data point to figure it out.. any help?

Re: Curve calculation help

Posted: Wed Jan 20, 2010 10:46 pm
by Alyosha
rayiner wrote:Depending on your school (eg: NU) your curve may not be normally distributed. For most schools, the upper tail is very spread out and the lower tail is very bunched-up.
So can somebody translate this for me? Does this mean that at NU, you can't use the standard deviation to determine the top 5% grade cutoff? Also, how do you know if you are at a school in which the curve is not normally distributed?

edit for spelling

Re: Curve calculation help

Posted: Wed Jan 20, 2010 11:32 pm
by ziggysmarley
..

Re: Curve calculation help

Posted: Wed Jan 20, 2010 11:36 pm
by YCrevolution
..

Re: Curve calculation help

Posted: Wed Jan 20, 2010 11:50 pm
by zanda
How about median and top-third for NYU?

A+: 0-2% (target = 1%)
A: 7-13% (target = 10%)
A-: 16-24% (target = 20%)
Maximum for A tier = 31%
B+: 22-30% (target = 26%)
Maximum grades above B = 57%
B: remainder
B-: 4-8% (target = 6%)
C/D/F: 0-5%

Is there enough information or do we need to know something about the correlation between an individual's grade in one class to his grade in another class?

(even if there is a way to calculate we'd seemingly need to fix the boundaries for each grade... probably best to go with the target numbers, right?)

Re: Curve calculation help

Posted: Thu Jan 21, 2010 1:15 am
by grobbelski
If each class curves to 3.2, is the overall median going to be a 3.2? Sorry, I don't remember shit from stats.

Re: Curve calculation help

Posted: Thu Jan 21, 2010 1:25 am
by RudeDudewithAttitude
Awesome thread everyone...btw, sorry op.

Re: Curve calculation help

Posted: Thu Jan 21, 2010 1:33 am
by omg
Here are some useful cutoffs (as a matter of statistics, they should mirror below the mean, so bottom 40% should very roughly speaking be as far below the mean as top 40% is above it):
Code:
5% 3.776
10% 3.648
15% 3.583
25% 3.483
33% 3.420
40% 3.369
50% 3.300
sealocust, you're very helpful as usual. what if i want to know my exact %? is it too difficult for a non-math-genius like me to figure it out?

and i think you mentioned that the uva curve shouldn't change. is that just because the b+ median is so strict and professors rarely deviate very much from their own/the enforced distributions around it, or is there something more to that?

thanks!

Re: Curve calculation help

Posted: Thu Jan 21, 2010 1:39 am
by OperaSoprano
Right. I'm not letting any of you guys near my grade distribution when all my grades are in. I just don't want to know! :|

Also, OP is not one of my classmates, because we curve to ~3.19. Failcurve.

Re: Curve calculation help

Posted: Thu Jan 21, 2010 1:47 am
by thesealocust
nm

Re: Curve calculation help

Posted: Thu Jan 21, 2010 1:56 am
by omg
sealocust, you're awesome. i figured it out. and that makes sense about the curve... thanks so much.