jQuery score card form to determine pass or fail
Personally I wouldn't change anything about the calculation itself. It all quite reasonable the way it is. 

There are just two things could be optimized concerning jQuery:


You should be using .closet() instead of .parents() since you only need the first (closest) matching parent and not all ancestors.
Also you can optimize assigning the event handler to the radio buttons by using .delegate() (or .on with jQUery 1.7) instead.


There are also a few things which personally I'd do differently:


In the HTML I'd use th elements for the question cells and td just for the options, allowing you to get rid of the classes webform-grid-question and webform-grid-option.
I'm not a big fan of using $ in variable names, especially if they don't point to a jQuery object.
I don't like using input elements for output. I'd use a "normal" element such as span or div (or if HTML5 is a option the new output element).