How can you calculate the points and then to result an exact percentage?

Question

I really want to know. Let’s say, your math teacher gives you a test, and she marks each subject different points.

Ok, and if I done let’s say, half of the test correct, then how can I calculate in the way that gives me the exact percentage?

I mean, 50% of the answer is correct. Or, 80% of the math home work is correct.

How you do this? it’s really interesting.

Sorry for adding a wrong tag, I didn’t know what kind of algebra or something that is part from Math, not physics or Chemistry. You know what I mean?

Do you mean like weighted averages? Or computing total points given a percentage? — Sean Roberson, Oct 10 '18 at 21:06
@SeanRoberson Weight? This does not have anything to do with math. I mean, computing… — Alex A, Oct 10 '18 at 21:07
@MichaelBurr evrica! But not quiet enouoh answer. I need a crystal clear example of how to do this. — Alex A, Oct 10 '18 at 21:10
@MichaelBurr First of all, you sir have miss understood me. I have no intention to argue with ANYONE!!! I only try to learn only of how to do this. — Alex A, Oct 10 '18 at 21:14
There isn't a unique way to combine percentages. There are multiple valid options that give different answers. — Michael Burr, Oct 10 '18 at 21:56

score 1 · Accepted Answer · answered Oct 10 '18 at 21:26

If the tests are of different sizes, 1 common way to create an acceptable answer is to calculate the geometric mean.

An example:

A student scores 2/5 on test 1, 3/7 on test 2 and 9/10 on test 3. (40%, 42%, 90%)

A "fair" representation of how well they did could be: $(\frac{2}{5} \times \frac{3}{7} \times \frac{9}{10})^{(1/3)} \approx 0.536\ =53.6\%$

This has the effect of trying to treat each exam equally regardless of total marks of each test.

Opinion - (this is the best way to do it)

Alternatively, you could add up all the scored marks and divide by the total possible marks:

$\dfrac{2+3+9}{5+7+10} \approx 0.636 = 63.6\%$

This has the tendency to bias the results towards whichever test has the most possible marks.

There is no perfect answer sadly.

Thanx for your answer. I’m content now. – Alex A Oct 10 '18 at 21:29 — Alex A, Oct 10 '18 at 21:29

1 Answers1