elcamino

I have a question for those taking Chemistry 3A or those who have already taken Chemistry 3A.

Apparently, Frechet doesnt curve each midterm but he curves after the final, so no one knows the standard deviation.

The mean for the 1st midterm was about 60% (around there i think) and for the 2nd midterm it was 44%.

Let's just say after the final and everything, I end up with 68.5% on the whole course. What are the possible ranges of grades that I could get. Any input will be fine. Thanks.

unlimitedx

Your range would totally depend on how well the rest of the class does.

elcamino

What if the range of the class is around 50-60%ish. How does standard deviation work and what is a deviant? What is the grade below/lower than a deviant?

unlimitedx

Usually 1 standard deviation is worth a letter grade in my curved classes.

Do you understand what range means? "A range of the class is around 50-60%" does not make sense.

TheRighteous

From what I see on Pick-A-Prof, Frechet's curve looks close to 30-30-25: 30% A's, 30% B's, 25% C's, and the rest are D's and F's.

elcamino

My mistake, not the range, but I was talking about the mean.

TheRighteous

If you score one standard deviation above the average, you are approximately at the 84th percentile of the class.

So, for the final grade, if your percentage is also one standard deviation above the class average, then you are guaranteed an A- or A, depending on the professor. We can assume this, because from past data it seems that Frechet gives out A's to the top 30% of the class.

Of course, this is all assuming that the grade distribution resembles a normal curve. If it doesn't, then the standard deviation doesn't mean much. The histogram for the second midterm shown in lecture does not depict a normal curve distribution, so I wouldn't care too much about the standard deviation.

elcamino

isnt 1 deviant above the mean a solid B?
and is 1 deviant normally about 10%?

System-AX

Please let me know how it turns out.

Student

Then that would be a ridiculous curve. 1 SD above the median is almost always an A.

elcamino

For a class that had 60% and 44% average for the first 2 midterms, respectively (total worth 50% of the course).
What kind of grade do you think i would get if my total grade ends up being 68% in the entire course after the final?

vicissitudes

Usually a lower-div weeder is curved to about a B-/C+, and a standard deviation is about a letter grade. So to illustrate:

mean 70%, standard deviation 15
This means:
A/A- = 85 - 100
B-/B+ = 70 - 85
C-/C+ = 55 - 70
D-/D+ = 40 - 55
F = 0 - 39

That's how it works in some classes I've seen. Doesn't mean it's how the Chem 3A class this year works, and some professors set the curve to whatever they feel like, but this might give you an idea of what the curve might look like.

TheRighteous

elcamino, did you try to do a regrade?

I think the grading on some of the questions was shady. Check out the answer key posted in Latimer and try to get some points back.

BlueElmo

well the SD on the second midterm was like 30 points or something, according to head GSI. But she said don't rely on SD.
God, I can't get mine back till tomorrow afternoon!!

TheRighteous

Yes, the grade distribution for this midterm is quite messed up.

I got mine back today. I am going to get a regrade on some of the problems with funky grading.