PLEASE ANSWERE A, B, AND C

You have a very good salary and a smart investment manager. She tells you that in only 6 years you can accumulate $688,530 from quarterly deposits of $20,000 into an account that has a historical return of 12% per year compounded quarterly. It seems like a stiff commitment, but one worth trying as you prepare for an early retirement from your current defense contractor engineering job. (a) Verify the 6-year time commitment if all other estimates are correct. (b) What is the total amount that you will deposit? (c) You are a cautious investor. Suppose the market does not perform as your investment manager predicts and the return is only 50% of what she predicted. What is the future value of your quarterly deposits?