An investor needs $24,000 in 18 years. (a) What amount should be deposited in a fund at the end of each quarter at 8% compounded quarterly so that there will be enough money in the fund? (b) Find the investor's quarterly deposit if the money is deposited at 6.9% compounded quarterly (a) The deposit should be $ (Do not round until the final answer. Then round to the nearest cent as needed)