In this paper, the representativeness bias is introduced and explained. The purpose is to investigate how representativeness bias can be applied in real world examples, such as healthcare programs and business operation management. Three studies, in two different fields, completed by other researchers, are provided to elaborate the effect of representativeness bias by empirical approach and rational approach. In each field, the experiments would show how the representativeness bias made people choose a different choice, how it guided people to make sub-optimal decisions. Through the studies presented, the benefits, disadvantages, and consequences of the use of representativeness bias are all explained. Through the data collected, representativeness bias is used very frequently, and in some cases, it does lead people to the sub-optimal choice. Also, some steps that people can take to reduce the effect of representativeness bias will also be shown. This allows people to make more accurate judgments not just in specific fields, but also in daily life, and minor matters.