Hello, nachos,
1. how do you calculate the mean of the following texts: A3, B7, C2, D1?
That's what you are trying.
Of course the codes have to be numerical. (1,2,3,4,5,...)
2. Wrong brackets in your equation. The "/" has to be inside the equation.
3. Why did you enter the assessment values? You do not use this in your survey.
4. The pictures can be anywhere in the Internet, as long as you enter the correct url.
If you upload them to your template you can use the placeholder {TEMPLATEURL} to enter the correct path.
I corrected the errors(codes only in grupo 2).
You can hide the boilerplate question; but only by adding the css class "hidden". I did that.
You should hide the equation questions as well.
Best regards
Joffm