20,27,34
The common difference is 7
Let the number of years after 2001 be x, then
1280000 + 19500x = 1700000
19500x = 1700000 - 1280000 = 420,000
x = 420000/19500 = 22 years.
x = 22 years.
Graph four shows the increase
300 represents the initial value or the value that you started with.
1.15 is the rate that the function increases by over t (time)