Question

184. A student estimated a mass to be 40 g. After carefully measuring, she
found the actual mass to be 45 g. What is the percent of error?

Answer 1

Answer:

$\boxed {\boxed {\sf About \ 11 \%}}$

Step-by-step explanation:

The formula for percent error is:

$\% \ error = | \frac{measured \ value - actual \ value }{actual \ value} | *100$

For this, the measured value is the estimation of 40 grams. The actual value is the true mass of 45 grams.

$measured = 40 \ g \\actual = 45 \ g$

$\% \ error = | \frac{40 \ g - 45 \ g }{45 \ g } | *100$

Solve the numerator.

• 40 grams - 45 grams = -5 grams

$\% \ error = | \frac{-5 \ g }{45 \ g } | *100$

Divide.

$\% \ error = | \frac{-5 \ g }{45 \ g } | *100$

$\% \ error = | -0.111111111| *100$

$\% \ error = 0.111111111*100\\\% \ error = 11.11111 \\\% \ error \approx 11$

The percent error is about 11%