On the Panel Questionnaire setup, the event managers have the option of selecting Percetage or Points to assign weights. It is recommended to select Percentage, as it will be a little simpler process to assign weights.
The total percentage of individually combined Pages, Groups, and Items must equal 100% (i.e. All Pages must add up to 100%). Collapse All of the sections and work from the top down assigning the percentages for Pages, then Groups, and finally individual items.
The Totals along the percentage column will show you where you stand with the setup, and remember to Save Progress frequently to avoid losing any changes. After saving progress the blue bar at the top of the page will also explain any areas which do not add up to the expected 100%.