The possible outcomes are:
LOSE $100, LOSE $80, LOSE $60, LOSE $40, LOSE $20,
BREAK EVEN $0,
WIN $20, WIN $40, WIN $60, WIN $80, WIN $100
The best outcome in this study is to WIN $100 and the worst outcome is to LOSE $100. This is biggest DIFFERENCE in this study. Compare each difference to the biggest difference by marking the line to match the proportion of the length to the ratio of the utility difference to the biggest difference.
Judge DIFFERENCES in utility compared to the biggest difference.