Weighted average score for exams and quizzes

[Eagle4112001]

Homework Statement

There are 2 exams of 100 marks each having weightage of 30%each and three quizzes of 30 marks each and weightage for the whole quiz is 40%.what is the weighted average score

Relevant Equations

Any help is appreciated

 

[PeroK]

What if the exams were 10 marks each?

 

[Eagle4112001]

What if the exams were 10 marks each?

Nah,it's 100.even if it is 10 marks,the problem is same.

 

[PeroK]

Nah,it's 100.even if it is 10 marks,the problem is same.

The problem looks a lot worse: 30% of 10 plus 30% of 10 plus 40% of 90 equals 42, which is a long way short of 100.

 

[Eagle4112001]

Yup,

The problem looks a lot worse: 30% of 10 plus 30% of 10 plus 40% of 90 equals 42, which is a long way short of 100.

 

[PeroK]

Why do you think that 30% of something plus 30% of something else plus 40% of anything else must equal 100?

 

[PeroK]

Anyway, with that marking scheme you have a maximum score of $96$. You could leave it like that or scale up by a factor of $100/96$ to get a total score of $100$.

I think you were fooled because 96 is close to 100, but it could have been anything: 42, 75, 1260, whatever.

 

[PeroK]

PS there may be two ways to interpret the weighted average in this case. First, we could have weighings of $0.3, 0.3$ and $0.4$ respectively, which is what you've done.

Altenatively, we could require that the third weighting means that a full score of $90$ in the tests gives an overall scaore of 40%. This means that the third weighting would be $40/90$.

I'm not sure which of these is intended.

 

[haruspex]

Homework Statement:: what is the weighted average score?

I cannot figure out what is being asked for.
If a component is "weighted 30%" it means a max score on that component would give 30% of the max overall mark. But we are not given a max overall mark.
If we presume "100%" then given an actual score of X out of Y on the component then this would contribute X/Y*30% to the overall result. So sensible questions might be:
- If Freddy scored (list of five scores) what was his overall percentage?
- How should each of the five scores be adjusted before adding them?

But the question asks for a single number.
If it means the max weighted average score then that would be whatever you choose it to be, 100%, 100, 96, 10...

Btw, there is no such word as "weightage". It's just "weight".