Find the present values of these ordinary annuities. Discounting occurs once a year. Do not round intermediate calculations. Round your answers to the nearest cent. a. $800 per year for 16 years at 8%. $ b. $400 per year for 8 years at 4%. $ C. $500 per year for 8 years at 0%. $ d. Rework previous parts assuming they are annuities due. Present value of $800 per year for 16 years at 8%:$ Present value of $400 per year for 8 years at 4%: $ Present value of $500 per year for 8 years at 0%: $