Mr.X has just celebrated his 30th birthday. He plans to retire on his 65th birthday. He has determined that he will need a total of $400,000 at that time to fund his retirement. a) His company offers a 401k retirement plan that earns 5% compounded monthly. How much (rounded to the nearest dollar) should Mr. X deposit at the end of each month to achieve his retirement goal? b) Assume that upon reaching age 65, Mr. X has attained his goal and has a total of $400,000 in the bank. He now wishes to purchase an annuity that will make monthly payments for 25 years (until he reaches age 90); at the end of that time, the account will be used up. Assuming that he can continue to earn 5% compounded monthly, what monthly payment will he receive