Final answer:
To calculate the percent error between the actual length of 76.49 cm and the measured length of 70.48 cm, we find the absolute error first and then divide by the actual length and multiply by 100. The percent error in this case is approximately 7.86%, which means that option b. 7.85% is the correct answer after rounding.
Step-by-step explanation:
The student has asked to calculate the percent error between the actual length of 76.49 cm and the measured length of 70.48 cm. To find the percent error, we first calculate the absolute error, which is the difference between the actual value and the measured value. Then we divide the absolute error by the actual value and multiply by 100 to get the percent error.
The absolute error is:
|76.49 cm - 70.48 cm| = 6.01 cm.
Now, calculate the percent error:
Percent error = (Absolute error / Actual value) × 100
Percent error = (6.01 cm / 76.49 cm) × 100
Percent error = 0.0786 × 100
Percent error = 7.86%.
Therefore, the correct answer is b. 7.85%, which is rounded to two decimal places.