When Angela turned 10, her parents deposited $5,000 in a college fund for her. When Angela enrolled in college at 18, her account had $6,800 to help pay her expenses. If the account paid simple interest, what was the annual interest rate?

Answer:The annual interest rate was 4.5% in Angela's college fund.Step-by-step explanation:1. Let's review the data given to us for solving the question:Investment when Angela was 10= US$ 5,000Duration of the investment = 8 years Balance of the account when Angela turned 18 = US$ 6,8002. Let's find the annual interest rate of this investment after 8 years or 20 quarters, using the following formula:FV = PV * (1 + r) ⁿPV = Investment when Angela turned 10 = US$ 5,000FV = Balance of the account when Angela turned 18 = US$ 6,800number of periods (n) = 8Replacing with the real values, we have:6,800 = 5,000 * (1 + r) ⁸6,800/5,000 = (1 + r) ⁸ (Dividing by 5,000 at both sides)34/25 = 1⁸ + r⁸ 34/25 - 1 = r⁸ (1⁸ = 1)34/25 - 25/25 =r⁸ (1 = 25/25)9/25 =  r⁸0.36 = r⁸ (9/25 = 0.36)⁸√0.36 = ⁸√r⁸0.045 = rr = 4.5%The annual interest rate was 4.5% in Angela's college fund.