I am sending a survey to supervisors, I want to give more value to the response based on number of employees working under each supervisor, how?!
It sounds like you are trying to do some basic math in your survey? If so, I think this help article will be a good place to start:
This might be easier to do in the response analysis phase using MS Excel. My group would probably export the results as a spreadsheet, sum up the reporting values, and then multiply that sum by what ever factor was appropriate. The only question would be how to identify the responses so that the appropriate factor could be applied.