1. How much will $800 deposited into a savings account at the end of each month be worth after 2 years at 6% interest compounded monthly?

2. How much will $3,500 deposited at the beginning of each 3-month period be worth after 7 years at 12% interest compounded quarterly?

3. What amount must be deposited now to withdraw $200 at the beginning of each month for 3 years if interest is 12% compounded monthly?

4. How much must be deposited now to withdraw $4,000 at the end of each year for 20 years if interest is 7% compounded annually?