I don't know how to solve 2-4, help would be very appreciated!

2. On January 1 of the current year, Southwest Inc. adopts a plan to accumulate funds for environmental improvements to occur 4.5 years in the future, at an estimated cost of $5,600,000. Southwest plans to make four equal annual deposits in a fund that earns interest at 10% compounded annually. The first deposit is made on July 1 of the current year. Compute the amount of the annual deposit

3. Hanks Inc. establishes a debt retirement fund to retire debt of $72,820. Hanks makes threeequal annual contributions of $56,000, starting on January 1 of the current year. The fund earns interest at 10% compounded annually. The $72,820 debt must be paid on December 31, three years later. What is the balance of the fund at December 31 in three years?

4. Gold Inc. invests $28,000 today in a mutual fund. Gold anticipates leaving this fund alone for 12 years. The fund is increased each year-end by specified compound interest rates as follows: years 1 to 4 inclusive, 8%; 5 to 8 inclusive, 9%; and 9 to 12 inclusive, 10%. Compute the fund balance at the end of year 12.