You are considering a project that has been assigned a discount rate of 7%. If you start the project today, you will incur an initial cost of $472 and will receive cash inflows of $355 a year for 3yrs. If you wait one year to start the project, the initial cost will rise to $530 and the cash flows will increase to $386 a year for 3yrs.

What is the value of the option to wait? (the correct answer is -8.24 but I need to know the steps to get this answer)