$($Present value$)$ What is the present value of the following future amounts?

a$.$ $$600$ to be received $10$ years from now discounted back to the present at $11$ percent

b$.$ $$300$ to be received $7$ years from now discounted back to the present at $9$ percent

c$.$ $$1,050$ to be received $12$ years from now discounted back to the present at $3$ percent

d$.$ $$1,050$ to be received $5$ years from now discounted back to the present at $19$ percent