Answer:
13.05%
Step-by-step explanation:
The value of an ordinary annuity earning interest compounded annually is ...
A = P((1 +r)^n -1)/r . . . . . interest rate r for n years on principal payments P
For this account, the balance after 5 years will be ...
A = 3000((1 +.07)^5 -1)/0.07 = 3000·5.750739
The sum of payments is ...
payment total = 3000·5
Then the amount of interest is ...
3000·(5.750739 -5) = 3000·0.750739
and the fraction that is of the account balance is ...
(3000·0.750739)/(3000·5.750739) × 100% ≈ 13.05%
About 13.05% of the balance is interest earned.
