1. **Problem statement:** Chang invests 4100 at an interest rate of 1.31% per year for 3 years with no withdrawals. We want to find: (a) The amount of money in the account after 3 years. (b) The interest earned after 3 years. 2. **Formula used:** For compound interest with no withdrawals, the amount after $t$ years is given by: $$ A = P \left(1 + \frac{r}{100}\right)^t $$ where: - $P$ is the principal (initial amount), - $r$ is the annual interest rate (in percent), - $t$ is the time in years, - $A$ is the amount after $t$ years. 3. **Calculate the amount after 3 years:** Given $P=4100$, $r=1.31$, $t=3$: $$ A = 4100 \left(1 + \frac{1.31}{100}\right)^3 = 4100 \left(1 + 0.0131\right)^3 = 4100 \times 1.0131^3 $$ Calculate $1.0131^3$: $$ 1.0131^3 = 1.0131 \times 1.0131 \times 1.0131 $$ Calculate stepwise: $$ 1.0131 \times 1.0131 = 1.0264 \quad (rounded) $$ $$ 1.0264 \times 1.0131 = 1.0401 \quad (rounded) $$ So, $$ A = 4100 \times 1.0401 = 4264.41 \quad (rounded) $$ 4. **Calculate the interest earned:** Interest $I$ is the amount minus the principal: $$ I = A - P = 4264.41 - 4100 = 164.41 $$ **Final answers:** (a) Amount after 3 years: $4264.41$ (b) Interest earned after 3 years: $164.41$