Question

What is the percentage error of length measurement of 0.229cm if the correct value is 0.225cm

Answer 1

Percent error is the difference between the measured and known value, divided by the known value, multiplied by 100%.

So first, we take our measured value, .299 cm, minus our known value, .225 cm.

.299 cm - .225 cm=.004 cm

Next, we divide that by our known value

$\frac{.004}{.225}=.0177777778$

Finally, multiply your answer by 100

.0177777778 x 100= 1.77777778 %

Round to three significant figures, and you're done.

=1.78 % error

Answer 2

% error = 2 %

$\% \text{error} = \frac{\text{0.225 cm} - \text{0.229 cm}}{\text{0.225 cm}} \times100 \% = \frac{|-0.004|}{0.225} \times 100 \% = 2 \%$