To calculate the percent error of Camila's measurement, we can use the formula for percent error:
\[ \text{Percent Error} = \left( \frac{|\text{Measured Value} - \text{Actual Value}|}{\text{Actual Value}} \right) \times 100 \]
In this case:
- Measured Value = 17.5 inches
- Actual Value = 18.5 inches
First, we find the absolute error:
\[ |\text{Measured Value} - \text{Actual Value}| = |17.5 - 18.5| = |-1.0| = 1.0 \text{ inches} \]
Next, we substitute the absolute error and the actual value into the percent error formula:
\[ \text{Percent Error} = \left( \frac{1.0}{18.5} \right) \times 100 \]
Now, we will compute the fraction:
\[ \frac{1.0}{18.5} \approx 0.054054 \]
Now, multiply by 100 to get the percent error:
\[ 0.054054 \times 100 \approx 5.4054 \]
Rounding to the nearest tenth of a percent:
\[ \text{Percent Error} \approx 5.4% \]
Thus, the percent error of the measurement is
\[ \boxed{5.4%} \]