Calculate the present value of the following annuity streams: a. $6,000 received each year for 4 years on the last day of each year if your investments pay 6 percent compounded annually b. $6,000 received each quarter for 4 years on the last day of each quarter if your investments pay 6 percent compounded quarterly. c. $6,000 received each year for 4 years on the first day of each year if your investments pay 6 percent compounded annually d. $6,000 received each quarter for 4 years on the first day of each quarter if your investments pay 6 percent compounded quarterly. (For all requirements, do not round intermediate calculations. Round your answers to 2 decimal places. (e.g., 32.16)) Present value 20,790.63 a b. Present value Present value C d. Present value