Problem:

What is the present worth of the following series of payments?

1) $800 at the end of each year for 12 years, at 5.8% interest compounded annually.

2) $2500 at the end of each year for 10 years, at 8.5% interest compounded annually.

3) $900 at the end of each year for 5 years, at 7.25% interest compounded annually.

4) $5500 at the end of each year for 8 years at 8.75% interest compounded annually

Explain in detail and provide all calculation.