Question on the book titled Systems Analysis and Design - An Object Oriented Approach with UML 5th Edition. Chapter 2, page 50, Figure 2-6. Could you please explain how were the PV OF BENEFITS values for each year (2015-2019) calculated? I know the formula for the Present Value (PV) = Amount/(1+ interest rate)^n. I just don't know what interest rate and n was used for each year. For example, in 2015, how did they come up with the PV OF BENEFITS of 619,417 from the TOTAL BENEFITS of 638,000? What were interest rate and n? Thanks.