5. How long will it last? Suppose a retirement account starts with a $ 500,000 balance. The owner wishes to withdraw $1000 each month to pay for expenses. Express the changing account balance in terms of actuarial annuity notation. Determine when the account balance will be depleted assuming: (a) an annual interest rate of 2% compounded monthly (b) an annual interest rate of 4% compounded monthly an annual interest rate of 6% compounded monthy (c) aII