Consider a project with free cash flows in one year of $90,000 in a weak economy or $117,000 in a strong economy, with each outcome being equally likely. The initial investment required for the project is $80,000, and the project's cost of capital is 15%. The risk-free interest rate is 5%. Suppose that you borrow only $45,000 in financing the project. According to MM proposition II, what is the firm's equity cost of capital?

(PLEASE provide formulas, Step-by-step process for all sections/parts, **don't use spreadsheet, I need to see the complete work out for all parts**)