To calculate Teresa’s percent error, we first find the absolute error, which is the difference between the estimated height and the actual height:
\[ \text{Absolute Error} = \text{Estimated Height} - \text{Actual Height} = 18 , \text{feet} - 16 , \text{feet} = 2 , \text{feet}. \]
Next, we calculate the percent error by dividing the absolute error by the actual height and then multiplying by 100:
\[ \text{Percent Error} = \left( \frac{\text{Absolute Error}}{\text{Actual Height}} \right) \times 100 = \left( \frac{2}{16} \right) \times 100 = 12.5%. \]
Thus, Teresa’s percent error is approximately 12.5%.