This section of the survey asks you about the rate you were paid for the work in USD. Remember you can retake the survey for multiple jobs.
If it was a single piece, please simply answer for that piece of art.
If it was a commission for a whole batch of art, you may need to do some math--sorry! For a batch, please work out the rate per piece you were paid. So that we can standardize these numbers, please consider a batch to be measured in QUARTER PAGE pieces and divide accordingly. So if the batch was 2 full pages and 8 quarter pages, that's 16 quarter pages. Take the amount you were paid for the batch and divide by 16.