Average calculations are NOT correct (solved)

I have a major problem with the 'averages'. Please look at this example.

The first student had a 2/10 for his first test. His second test was a 18/20. Together it's 20/30. The average should be 66,66% or 6.6/10. But the calculus (average) says it's 5.50.

What went wrong? How do I get the right average.

Thanks,
Micha

Welcome Micha,
From what I see , it seems correct, (2/10 + 18/20) /2 = 11/20 which is 5.50
I think what you did wrong was 2/10 +18/20 , that equals 22/20, not 20/30
If something is still not clear please let me know!
Thanks for contacting us

Thank you for the quick answer! But I what I wrote was what I meant; 2/10 + 18/20= 20/30.

One test is on 10 and the other on 20. If it were to be 4/20 + 18/20 then the average would be 50%. But I want the first test to be on 10 and not on 20. In the last case, the average is not 50%.

Look at the example of the other student: same problem.

I have a lot of tests that vary in 'weight' - so they can't be brought back on the same level: f.i. an exam (100 points) is not the same as a reading exercise (5 points). In the actual 'calculus' system of iDoceo the reading exercise would be changed to 100 points. The average would then be based on 2 tests on 100 points.

So my question stays: how can you solve the 'average' problem?

thx

Hi Micha,

The actual calculus behind the scenes in iDoceo are more powerful and there is a lot more than meets the eye , it allows lots of combinations, not just simple averages.

On each operation there is a conversion to an abstract grade , which is neither the input or the output grade type so that operations between them can take place with "homogenic" types.

There is no problem in mixing exams with base 5 or 10, or 100 or even texts in between. That is taken into account and it works.

The problem is that in your calculus you are not doing an average but an addition.

So, you need two steps to achieve what you need:
- First , create a column with the total of all the exams with no grade type, and tapping on the 'Add All' button(Please note there is no Grade type on the columns)



- Second add a column that converts your addition into the base you need, in this example, base 30



- This is how the From 0 to 30 is configured, note the Threshold value



Let me know if we finally got that right!
Cheers

Micha,
There is actually a faster way that does not involve an intermediate column.
Here the image. The configuration From 0 to 30 stays the same as stated in previous
post.