You have ​$5800 to invest today at 11​% interest compounded annually.

a. Find how much you will have accumulated in the account at the end of​ (1) 6 ​years, (2) 12 ​years, and​ (3) 18 years.

b. Use your findings in part a to calculate the amount of interest earned in​ (1) the first 6 years​ (years 1 to 6​), ​(2) the second 6 years​ (years 7 to 12​), and​ (3) the third 6 years​ (years 13 to 18​). c. Compare and contrast your findings in part b.  

Explain why the amount of interest earned increases in each succeeding 6 dash year period.