Can I add a feature in a radio button grid question that would do a sum of all the options selected.
Say my columns have options as 5%,10%,15% and so on. I want the survey to sum up all the percentages selected across the multiple rows and show up an error if sum total is less than or more than 100%
The short answer is, “yes!”
Alternatively, if you are comfortable moving away from the Radio Button Grid question type, the Continuous Sum question actually does something very close to what you describe The only major difference is that respondents would be typing in a textbox, instead of selecting radio buttons.
I hope this helps to answer your question!