enter the known values and then press the appropriate key to find the unknown variable. Then, without clearing the TVM register, you can "override" the variable that changes by simply entering a new value for it and then pressing the key for the unknown variable to obtain the second answer. This procedure can be used in many situations, to see how changes in input variables affect the output variable. Also, note that you can leave values in the TVM register, switch to Begin Mode, press PV, and find the PV of the annuity due.) Do not round intermediate calculations. Round your answers to the nearest cent. a. $600 per year for 10 years at 14%. 5 b. $300 per year for 5 years at 7%. 5 c. $600 per year for 5 years at 0%. $ d. Now rework parts a, b, and c assuming that payments are made at the beginning of each year;, that is, they are annuities due. Present value of $600 per year for 10 years at 14%:$ Present value of $300 per year for 5 years at 7%:$ Present value of $600 per year for 5 years at 0%:$