Sanaa has been saving money in the same account for 20 years. She started with $3000. For the first 6 years, the account paid j(12) = 7% . For the next 7 years, it paid j(12) = 9%. For the last 7 it paid j(12) = 6% compounded.

a) How much money is in her account today?

b) Suppose the account had paid the same effective annual rate r for all 20 years, and that her starting balance and ending balance were as above. Solve for r (to 2 decimal places). (If your answer is 3.06% write 3.06 not 0.0306.

c) Write the formula you used to compute your answer to b)