Answer:
8.3%
Explanation:
The formula for Percentage error is given as:
|Measured value - True value|/True value × 100
The measured value = 13cm
The true value = 12cm
Hence:
Percentage error = |13 cm - 12cm|/12 cm × 100
= 1/12 × 100
= 8.3%
The percent error of Jessica's measurement is 8.3%