Final answer:
The balance of Ella's savings account after 4 years is approximately $2762.93.
Step-by-step explanation:
To find the balance of Ella's savings account after 4 years, we can substitute t = 4 into the function b(t) = 2500 * e^(0.025t). Using a calculator or a computing tool, we can evaluate this expression to find the answer.
Plugging in t = 4 into the function, we get:
b(4) = 2500 * e^(0.025 * 4)
b(4) = 2500 * e^(0.1)
Using a calculator or a computing tool, we can find that the value of e^(0.1) is approximately 1.10517. Multiplying this value by 2500 gives us the balance:
b(4) ≈ 2500 * 1.10517 = 2762.93
Rounding this answer to the nearest hundredth, the balance of Ella's savings account after 4 years is approximately $2762.93.