Javier currently has no money in his savings account that earns 5.64% per annum, compounded monthly. He plans to fund a 12-month round-the-world trip by making deposits of $1,350 into the account at the end of each month.

(a) Determine the balance of her account just after his 4^th deposit.

As soon as his balance first exceeds $70,000, Javier will stop making deposits and head off on a 12 month trip. Because regular payments are no longer made into the account, the interest rate will decrease to 4.8% per annum. Javier will make the same withdrawal at the end of each month, so that after the 12^th one his savings account balance will have fallen to $10,000.

(b) Determine the balance of his account when he stops making deposits.

( c) Determine the monthly withdrawal Javier will make on his trip

(d) Determine the total amount of interest that his savings account earned from the time Javier started saving for the trip until its end.