## Math-wiz help with curves

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stinger35

Posts: 614
Joined: Thu Jan 07, 2010 2:37 pm

### Math-wiz help with curves

I was wondering if anyone could tell me what these curves work out to be (i.e. 2.9, 3.0, whatever). I am sure it's not hard but I am absolutely terrible at Math (I thought that's why we went to law school)

A 10%-15%
B+ 20%-25%
B 25%-30%
C+ 20%-25%
C or below 15%-20%

and

A 12%-20%
B+ 21%-27%
B 25%-31%
C+ 16%-22%
C or below 10%-16%

Thanks dudes.

d34d9823

Posts: 1879
Joined: Wed Apr 14, 2010 2:52 pm

### Re: Math-wiz help with curves

Not that hard, but if you want a precise answer, you need more precise distributions. I've commented in the calc.

stinger35 wrote:I was wondering if anyone could tell me what these curves work out to be (i.e. 2.9, 3.0, whatever). I am sure it's not hard but I am absolutely terrible at Math (I thought that's why we went to law school)

A 10%-15% 4*.125
B+ 20%-25% 3.3*.225
B 25%-30% 3*.275
C+ 20%-25% 2.3*.225
C or below 15%-20% unsure what to use here, call it 1.5*.175
Sum them and we get 2.84

and

A 12%-20%
B+ 21%-27%
B 25%-31%
C+ 16%-22%
C or below 10%-16%

do same thing here and get 2.88
Thanks dudes.

pinkzeppelin

Posts: 231
Joined: Mon Dec 07, 2009 11:51 pm

### Re: Math-wiz help with curves

d34dluk3 wrote:Not that hard, but if you want a precise answer, you need more precise distributions. I've commented in the calc.

stinger35 wrote:I was wondering if anyone could tell me what these curves work out to be (i.e. 2.9, 3.0, whatever). I am sure it's not hard but I am absolutely terrible at Math (I thought that's why we went to law school)

A 10%-15% 4*.125
B+ 20%-25% 3.3*.225
B 25%-30% 3*.275
C+ 20%-25% 2.3*.225
C or below 15%-20% unsure what to use here, call it 1.5*.175
Sum them and we get 2.84

and

A 12%-20%
B+ 21%-27%
B 25%-31%
C+ 16%-22%
C or below 10%-16%

do same thing here and get 2.88
Thanks dudes.

This is good, but since the summation of the assumed percentiles don't sum to 1 for the first one, you are over estimating. Since the percentages sum to 1.025... multiply each by 1/1.025 and then run the calculation again. You get 2.78 for the first one. The second calculation is fine.

roofles

Posts: 97
Joined: Mon Feb 22, 2010 10:05 pm

### Re: Math-wiz help with curves

In the absence of minus grades, wouldn't the plus grades be 3.5 for a B+, 2.5 for a C+, etc.? My undergrad didn't issue minus grades and that is how they calculated gpa.

stinger35

Posts: 614
Joined: Thu Jan 07, 2010 2:37 pm

### Re: Math-wiz help with curves

roofles wrote:In the absence of minus grades, wouldn't the plus grades be 3.5 for a B+, 2.5 for a C+, etc.? My undergrad didn't issue minus grades and that is how they calculated gpa.

Yea, that actually is true. B+ is 3.5, C+ is 2.5, etc.

So I guess it needs to be recalculated. (I don't understand why they don't have minus grades. I would have much preferred A-'s over the two B+'s I received, if only for transfer purposes.

d34d9823

Posts: 1879
Joined: Wed Apr 14, 2010 2:52 pm

### Re: Math-wiz help with curves

stinger35 wrote:
roofles wrote:In the absence of minus grades, wouldn't the plus grades be 3.5 for a B+, 2.5 for a C+, etc.? My undergrad didn't issue minus grades and that is how they calculated gpa.

Yea, that actually is true. B+ is 3.5, C+ is 2.5, etc.

So I guess it needs to be recalculated. (I don't understand why they don't have minus grades. I would have much preferred A-'s over the two B+'s I received, if only for transfer purposes.

Yes for school GPA, no for LSAC GPA. From how I read their chart LSAC counts +/- grades as += +.3, -= -.3

stinger35

Posts: 614
Joined: Thu Jan 07, 2010 2:37 pm

### Re: Math-wiz help with curves

d34dluk3 wrote:
stinger35 wrote:
roofles wrote:In the absence of minus grades, wouldn't the plus grades be 3.5 for a B+, 2.5 for a C+, etc.? My undergrad didn't issue minus grades and that is how they calculated gpa.

Yea, that actually is true. B+ is 3.5, C+ is 2.5, etc.

So I guess it needs to be recalculated. (I don't understand why they don't have minus grades. I would have much preferred A-'s over the two B+'s I received, if only for transfer purposes.

Yes for school GPA, no for LSAC GPA. From how I read their chart LSAC counts +/- grades as += +.3, -= -.3

True, but that doesn't matter for transferring. Any help figuring it out with the different numbers? I think it should be around a 2.8 for the first 2.9 for the second?

d34d9823

Posts: 1879
Joined: Wed Apr 14, 2010 2:52 pm

### Re: Math-wiz help with curves

stinger35 wrote:
d34dluk3 wrote:
stinger35 wrote:
roofles wrote:In the absence of minus grades, wouldn't the plus grades be 3.5 for a B+, 2.5 for a C+, etc.? My undergrad didn't issue minus grades and that is how they calculated gpa.

Yea, that actually is true. B+ is 3.5, C+ is 2.5, etc.

So I guess it needs to be recalculated. (I don't understand why they don't have minus grades. I would have much preferred A-'s over the two B+'s I received, if only for transfer purposes.

Yes for school GPA, no for LSAC GPA. From how I read their chart LSAC counts +/- grades as += +.3, -= -.3

True, but that doesn't matter for transferring. Any help figuring it out with the different numbers? I think it should be around a 2.8 for the first 2.9 for the second?

What pinkzep said.

Tautology

Posts: 434
Joined: Thu Mar 18, 2010 12:40 pm

### Re: Math-wiz help with curves

stinger35 wrote:
d34dluk3 wrote:
stinger35 wrote:
roofles wrote:In the absence of minus grades, wouldn't the plus grades be 3.5 for a B+, 2.5 for a C+, etc.? My undergrad didn't issue minus grades and that is how they calculated gpa.

Yea, that actually is true. B+ is 3.5, C+ is 2.5, etc.

So I guess it needs to be recalculated. (I don't understand why they don't have minus grades. I would have much preferred A-'s over the two B+'s I received, if only for transfer purposes.

Yes for school GPA, no for LSAC GPA. From how I read their chart LSAC counts +/- grades as += +.3, -= -.3

True, but that doesn't matter for transferring. Any help figuring it out with the different numbers? I think it should be around a 2.8 for the first 2.9 for the second?

I'll do the first one for you, and maybe you can do the second; the steps are pretty straightforward.

First, you'll want to decide on a precise percentage who gets each grade. Even if you don't know exactly what they are, you want to pick one for the calculation. Probably the best thing to do (as was done above) is to just go right down the middle (take the average) of the two ends of the range. Thus if we know that 10%-15% get A's, we'll make that number 12.5%. Doing this for all of them in the first example yields

A 12.5%
B+ 22.5%
B 27.5%
C+ 22.5%
F-C 17.5%

A problem arises here though, because those numbers don't add up to 100%, but 102.5%. I will fix this at the end of my calculation because it's easier there. Since this problem doesn't exist with the second set of numbers you provided, you won't have to worry about that step.

Now, remember that 12.5% can be expressed in decimal form as .125. Similarly, 22.5% can be expressed as .225. We need to convert the percentages we have above to decimals so that we can multiply them by the value given for each letter grade. That looks like this.

A .125
B+ .225
B .275
C+ .225
F-C .175

Now all we have to do is multiply each of those numbers by the value assigned to each letter grade, and add those together. Thus we get:

A .125 x 4.0 = .5
B+ .225 x 3.5 = .7875
B .275 x 3.0 = .825
C+ .225 x 2.5 = .5625
F-C .175 x 1.5 = .2625

That last category, everything below a C+, doesn't have a specific number attached to it like the rest, so we sort of have to guess. I used 1.5, the value used above, but in reality it may be higher than 1.5 if Fs and Ds are very rare, and lower than 1.5 if Fs and Ds are common.

Finally, we just add all those numbers up and get 2.94 (rounded). That would be the average GPA given that curve, and is the end of the steps for the second set of numbers, but since we had a problem (mentioned above) with our numbers not adding up to 100%, we have to divide it by 1.025 (102.5%). This leaves us with 2.87 (rounded) for our average GPA.