Question

A graduated cylinder actually contains 7.5 milliliters of water. When Han measures

the volume of the water inside the graduated cylinder, his measurement is 7

milliliters. Which of these is closest to the percent error for Han’s measurement?

(1pt) 7.RP.A.3

a. 107.1%

b. 93.3%

c. 7.1%

d. 6.7%

Answer 1

To calculate the percent error, you can use the formula:

\[
\text{Percent Error} = \left( \frac{|\text{Measured Value} - \text{True Value}|}{\text{True Value}} \right) \times 100
\]

In this case, the measured value is 7 mL and the true value is 7.5 mL.

1. Calculate the absolute error:
\[
|\text{Measured Value} - \text{True Value}| = |7 - 7.5| = 0.5 \text{ mL}
\]

2. Plug the values into the percent error formula:
\[
\text{Percent Error} = \left( \frac{0.5}{7.5} \right) \times 100
\]

3. Calculate the ratio:
\[
\frac{0.5}{7.5} = 0.0667 \quad \text{(approximately)}
\]

4. Multiply by 100 to get the percent:
\[
0.0667 \times 100 \approx 6.67\%
\]

Thus, the closest percent error for Han’s measurement is:

**d. 6.7%**