Income from cardboard recycling at Fort Bliss has been increasing at a constant rate of $800 in each of the last 4 years. If this year's income (i.e., end of year 1) is expected to be $4000 and the income trend continues through year 6, (a) what will the income be 4 years from now and (b) what equal amount in years 1 through 6 is the equivalent of all the income over that time period at an interest rate of 8% per year