I have been wanting to calculate what my mark is in a course, and I have been using the method below. I want to make sure that I am doing it correctly.

I take my mark as a percentage and multiply by its weight as a decimal. I do this for all of my marks and add them up.

Example:

Midterm - 75% * 0.15 = 11.25
Lab - 90% * 0.0375 = 3.375
.
.
.

I do this for all of my marks and add up the values on the right to get what I have out of 100. As we complete more assignments, the value goes up until we have all of the entries to get my final mark.

Is this the correct way of doing this calculation? Its just a simple weighted average.

Thanks

Yup that looks correct. I normally go 15 x 0.75 = 11.25, but it's the same thing =)

thanks so much - Excel works wonders when keeping track of marks

I just wanted to be sure I was working out the numbers correctly.

Cheers

how would you know what percentage you have right now? (not including stuff which hasn't happened??)

Originally Posted by Afzal

how would you know what percentage you have right now? (not including stuff which hasn't happened??)

You can divide the numbers you add up on the right hand side by the maximum allotted points.

For example, using the example above;

Midterm: 11.25/15 Max
Lab: 3.375/3.75 Max

11.25 + 3.375 / (15 + 3.75) = 78% in the course currently.

Sorry to drive the point home like this, but it's kind of a slow day for Macinsiders, and I've allocated myself a half hour break. :p So I'm going to make the most of it, haha.

Originally Posted by Ivan Q.

Yup that looks correct. I normally go 15 x 0.75 = 11.25, but it's the same thing =)

Technically, although rossignol is also correct, Ivan Q's way is the 'intuitive' way of thinking about it:

You take the total value of your test (say 15% of your final grade), then find out what value you've earned (by say, multiplying by 0.75, corresponding to 75%).

But of course, since real numbers are associative (ie. x(yz) = (xy)z), the two methods are equivalent:

15 x 0.75 (Ivan Q's)
=15 x (.001 x 75)
=(15 x .001) x 75 (By Associativity)
=0.15 x 75 (rossignol's)

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To Afzal: Greg's method is 100% correct, but be careful of misleading grades!

Case in point: In my first year anatomy class, we had bi-weekly quizzes, labs (attendance marks) followed by one final exam (worth 60% of the term's grade), for each term.

In my first term, I attended all my labs and achieved high grades on my quizzes...calculating my grade as Greg has done, I had a 98% going into my final.

This mislead me into thinking I was well prepared for my exam...which as it turned out, I was not. Conversely, if I had used the alternative method, to find out I only had approx. 39%/40%, then I would have said "Hmm...I could still potentially fail the course."

Needless to say I learned from the experience and it hasn't steered me wrong, so I just wanted to point that out. (:

Originally Posted by PTGregD

You can divide the numbers you add up on the right hand side by the maximum allotted points.

For example, using the example above;

Midterm: 11.25/15 Max
Lab: 3.375/3.75 Max

11.25 + 3.375 / (15 + 3.75) = 78% in the course currently.

isnt this essentially the same as taking out the average of all the marks regardless of the weightage?

No...you could have a 30% midterm and gotten 50%, and a 2% assignment and gotten 100.

By taking the average of the marks regardless of weight your mark would be 75%. By taking the average and factoring in the weight, your mark would be
(0.3*50)+(0.02*100) / (32) = 53%

Originally Posted by Afzal

isnt this essentially the same as taking out the average of all the marks regardless of the weightage?

You missed one crucial step, I think that's what's giving the confusion here:

When Greg is saying

Midterm: 11.25/15 Max
Lab: 3.375/3.75 Max

the numerators (11.25 and 3.375) are weighted...they correspond to grades of 75% and 90% respectively (See the original post to see how these numbers were calculated).

If you took a grade regardless of weight (or in other words, they have the same weighting), you'd say they got one 75%, one 90%, then their grade is the average, [75 + 90] / 2 = 82.5%.

But as you might notice, the midterm was worth much much more than the lab...so this is clearly a bad assumption.

Originally Posted by Mowicz

You missed one crucial step, I think that's what's giving the confusion here:

When Greg is saying

Midterm: 11.25/15 Max
Lab: 3.375/3.75 Max

the numerators (11.25 and 3.375) are weighted...they correspond to grades of 75% and 90% respectively (See the original post to see how these numbers were calculated).

If you took a grade regardless of weight (or in other words, they have the same weighting), you'd say they got one 75%, one 90%, then their grade is the average, [75 + 90] / 2 = 82.5%.

But as you might notice, the midterm was worth much much more than the lab...so this is clearly a bad assumption.

got it.

i just want to be sure of something. i m going into an exam with i high mark and the exam is worth 50%. an i have 48%/50% with midterms and assignments, does that mean i only need a 4% on the exam to pass the course.?

just to be sure: failing an exam doesnt mean i fail a course, right?

Originally Posted by Lizliz

i just want to be sure of something. i m going into an exam with i high mark and the exam is worth 50%. an i have 48%/50% with midterms and assignments, does that mean i only need a 4% on the exam to pass the course.?

just to be sure: failing an exam doesnt mean i fail a course, right?

It depends on the course, some you have to pass the final exam to pass the course and others your don't. It should say in the course syllabus.

Although I would think if you're getting 96% you could get a passing mark, let alone more than 4% on the exam without any studying.

Originally Posted by Alchemist11

Although I would think if you're getting 96% you could get a passing mark, let alone more than 4% on the exam without any studying.

yes, but i just want to be sure. i'm considering a worst case scenario. i obviously won't get 4% but there is a chance of me failing...