Answer:
about 12.75%
Step-by-step explanation:
Let r represent the annual rate of return. Compounded annually for 18 years, the account multiplier is (1+r)^18. Then we have ...
26,000 = 3,000(1+r)^18
(26,000/3,000)^(1/18) = 1+r . . . . . . divide by 3000, take the 18th root
(26/3)^(1/18) -1 = r ≈ 12.7465%
Ezio's account earned about 12.75% annually.