Answer:
12.18%
Step-by-step explanation:
Present value = $34,700
Future Value = $173,500
Time (n) = 14 years
Interest Rate = i
Future Value = Present Value * (1+i)^n
$173,500 = $34,700 * (1 + i)^14
(1 + i)^14 = $173,500/$34,700
(1 + i)^14 = 5
1 + i = 5^(1/14)
1 + i = 1.1218284
i = 1.1218284 - 1
i = 0.1218284
i = 12.18%
So, the annual interest rate she must earn is 12.18%.