Please answer correct calculation asap plz

Don't answer by pen paper plz

1. Consider a project that would involve purchasing marginal farmland that would then be allowed to return to wetlands capable of supporting migrant birds. Researchers designed a survey to implement the dichotomous choice method. They reported the following data: Stated Price Fraction of (annual Respondents payment in Accepting dollars) Stated Price (percent) What is the mean willingness to pay for the sampled population if the low-end of each interval is used? What is the mean willingness to pay for the sampled population if the mid-point of each interval is used? What is the mean willingness to pay for the sampled population if the high-end of each interval is used