Question

Martha estimated there were 96 marbles in a jar for a contest. The actual number of marbles in the jar was 118. What was the percent error of Martha's estimation?
A.
22%
B.
22.92%
C.
18.64%
D.
81.36%

Answer 1

To calculate the percent error of Martha's estimation, we can use the formula for percent error:

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

Where:
- Estimated Value = 96 (Martha's estimate)
- Actual Value = 118 (actual number of marbles)

Plugging in the values:

\[
\text{Percent Error} = \left( \frac{|96 - 118|}{118} \right) \times 100
\]

Calculating the absolute difference:

\[
|96 - 118| = 22
\]

Now substituting back into the formula:

\[
\text{Percent Error} = \left( \frac{22}{118} \right) \times 100
\]

Calculating the fraction:

\[
\frac{22}{118} \approx 0.1864
\]

Now, converting this to a percentage:

\[
0.1864 \times 100 \approx 18.64\%
\]

Thus, the percent error of Martha's estimation is:

**C. 18.64%**