Question

Teresa estimates that the height of a giraffe in a zoo is 18 feet. In fact, it is 16 feet tall. What is Teresa’s percent error? Use proportional relationships to solve the problem. Be sure to show all your work, provide your answer as a percentage, and round your answer to the nearest tenth. (4 points)

Answer 1

To calculate Teresa's percent error, we can use the following formula for percent error:

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

Given:
- Estimated Value = 18 feet
- Actual Value = 16 feet

First, we find the absolute difference between the estimated value and the actual value:

\[
|\text{Estimated Value} - \text{Actual Value}| = |18 - 16| = 2 \text{ feet}
\]

Next, we substitute the values into the percent error formula:

\[
\text{Percent Error} = \left( \frac{2}{16} \right) \times 100
\]

Now, we calculate the fraction:

\[
\frac{2}{16} = 0.125
\]

Next, we multiply by 100 to convert this to a percentage:

\[
0.125 \times 100 = 12.5
\]

Thus, Teresa’s percent error is approximately:

\[
\boxed{12.5\%}
\]