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  • Subject: Non-Homework related Math question.
Subject: Non-Homework related Math question.

<3

Ok, so I was figuring out my grade for my college class, 50 percent of my grade is homework and the other 50 percent is tests.

When I added all of my grades together and divided by 13(the number of tests and homeworks), I got a 78 which is a BC, aka what I need to pass.

When he averaged the test grade, averages the homework grade and then divided by 2, he got a 76, which is a huge difference. Can anybody explain why doing it that way makes any difference? They are both worth the same amount of points so I thought they should average out the same.

I'm very stressed out right now, I emailed my teacher, waiting for his response, hopefully he gives me mercy.

  • 12.26.2012 10:43 PM PDT

From up here the city lights burn like a thousand miles of fire

that sounds oddly specific for a non-homework related question...

  • 12.26.2012 10:44 PM PDT
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PRAISE THE SUN!

Try PRAISING THE SUN!

  • 12.26.2012 10:45 PM PDT

<3


Posted by: Dualkiller9000
that sounds oddly specific for a non-homework related question...
This is not a homework problem. I'm trying to find out why my grade in my math class is different if I take the average of both grades and dividing by 2 instead of adding all the grades together and dividing by 13.

  • 12.26.2012 10:46 PM PDT

The total for the tests and homework might be the same, but it's also possible certain tests weigh more heavily on that 50% than others. That's what most classes do anyway.

  • 12.26.2012 10:46 PM PDT

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"Ignorance is a plague."

Close, but the plague killed those infected with it, and the ignorant are still alive.
I wish ignorance was a plague.

Posted by: Toxifies
Ok, so I was figuring out my grade for my college class, 50 percent of my grade is homework and the other 50 percent is tests.

When I added all of my grades together and divided by 13(the number of tests and homeworks), I got a 78 which is a BC, aka what I need to pass.

When he averaged the test grade, averages the homework grade and then divided by 2, he got a 76, which is a huge difference. Can anybody explain why doing it that way makes any difference? They are both worth the same amount of points so I thought they should average out the same.

I'm very stressed out right now, I emailed my teacher, waiting for his response, hopefully he gives me mercy.

The number of tests and homework assignments isn't the same, that's what's changing things.

Simpler example:
Test marks: 60, 80
Homework marks: 70, 80, 90

The average mark on the tests is 70
The average on the homework is 80
If you average both of them (the right way to do it in this situation), the final mark is 75

If you just average everything, the final mark is 76.

tl:dr = he's right, you're wrong.

  • 12.26.2012 10:48 PM PDT

<3


Posted by: destroys u
Posted by: Toxifies
Ok, so I was figuring out my grade for my college class, 50 percent of my grade is homework and the other 50 percent is tests.

When I added all of my grades together and divided by 13(the number of tests and homeworks), I got a 78 which is a BC, aka what I need to pass.

When he averaged the test grade, averages the homework grade and then divided by 2, he got a 76, which is a huge difference. Can anybody explain why doing it that way makes any difference? They are both worth the same amount of points so I thought they should average out the same.

I'm very stressed out right now, I emailed my teacher, waiting for his response, hopefully he gives me mercy.

The number of tests and homework assignments isn't the same, that's what's changing things.

Simpler example:
Test marks: 60, 80
Homework marks: 70, 80, 90

The average mark on the tests is 70
The average on the homework is 80
If you average both of them (the right way to do it in this situation), the final mark is 75

If you just average everything, the final mark is 76.

tl:dr = he's right, you're wrong.

I never said he was wrong. The way he does it, that's my grade. I just want to know why :(. I mean it shouldn't make a difference if everything is worth the same.

  • 12.26.2012 10:51 PM PDT

Does anyone have lotion?
*Raises hand*
Is mayonnaise a lotion?

Probably special weighting on either certain assignments or certain types of assignments.

  • 12.26.2012 10:53 PM PDT

"There's a very fine line between not listening, and not caring. I'd like to think that I walk that line every day."

Posted by: Toxifies
I mean it shouldn't make a difference if everything is worth the same.
It's the nature of finding the difference of two averaged numbers and finding the difference of several (unaveraged) numbers.

I'd talk to your instructor and see if you can have it bumped up to a pass.

[Edited on 12.26.2012 10:54 PM PST]

  • 12.26.2012 10:53 PM PDT

Posted by: Toxifies
I mean it shouldn't make a difference if everything is worth the same.
Well that poster is likely right still.

Homework: 70% 70% 80% for three homeworks.
Tests: 70% 80% for two tests.

Homework average: 73.3%.
Test average: 75%.

Each one counts for 50% of your grade. So they're even. Which makes it a 74.17% average.

But if you do it your way, you're not taking into account that each category is worth 50%. You're basically saying a test is equal to a homework. That way would give you 74% flat.

So... yeah, it matters mate, because you get different numbers depending on how many tests and homeworks there are. Sorry.

[Edited on 12.26.2012 10:57 PM PST]

  • 12.26.2012 10:56 PM PDT

<3


Posted by: ICanHazRecon911
Probably special weighting on either certain assignments or certain types of assignments.
Nothing is weighted. When I average my tests grades and then average my homework grades and divide by 2, it comes out to a 76, but when I take all the grades and divide by 13 it's a 78. It's a huge difference that's stressing me out right now. All I can do is hope my professor will take mercy on me.

  • 12.26.2012 10:58 PM PDT

He may have gotten something wrong, lets say you get 6, 8, and 5, this sums 19 points out of 30, or 63.333 out of 100, now 8, 8, and 7, total 23 of 30, 76.666 out of 100, (63.333 + 76.666)/2 = 69.999 (70), I believe this is how it should be done, now with your description of the teacher´s method: 19 out of 30, 19/3= 6.999 (which could be theoretically equal to 7, but teacher math does not follow this) and 23/3= 7.999 (again there may or may not be some math rule applied here by your teacher) and (7.9+6.9)/2= 7.5

I think I have something wrong with my math, so just check that you are not taking for granted any rounding around there and ask the teacher for a full procedure on what he did, if you want some extra points try to get him to round some intermediate values to an upper number, be discrete though.

  • 12.26.2012 11:01 PM PDT

<3

Ok guys. I guess I figured out why it does that. Now all I can do is wait for my professor to respond to my email and tell me whether or not he will give me the extra 1.47 points.

  • 12.26.2012 11:02 PM PDT
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If you studied instead of wasting your time playing video games, you wouldn't have been in this situation.

  • 12.26.2012 11:23 PM PDT