Gerald Guanaco is 20 years old today and has decided to plan for his retirement. He intends making equal monthly deposits, each $300, into a bank account earning interest at the rate of 4.258% compounded once every two years. He intends the last of these deposits to occur on his 50th birthday. Thereafter, starting one month later, he will continue making monthly deposits (now $500 each) into the same account with the last $500 deposit occurring on his 65th birthday. a. How much will Gerald have in his bank account immediately after he has made the last $500 deposit?