Question

Simon is expecting a new baby sister. Simon predicts the baby will weigh 6 and one-half pounds at birth. Calculate the percent error of Simon's estimate if the baby's weight at birth is 8 and one-quarter pounds.(1 point)
Responses

0.21%
0.21%

25%
25%

−21%
negative 21 percent

21%

Answer 1

To calculate the percent error of Simon's estimate, you can use the following formula:

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

In this case, Simon's estimated weight (6.5 pounds) and the actual weight (8.25 pounds) can be substituted into the formula:

1. First, determine the difference between the estimated and actual weights:

\[
\text{Difference} = \text{Estimated Value} - \text{Actual Value} = 6.5 - 8.25 = -1.75
\]

2. Now, plug the values into the formula:

\[
\text{Percent Error} = \left( \frac{-1.75}{8.25} \right) \times 100\%
\]

3. Calculate the fraction:

\[
\frac{-1.75}{8.25} \approx -0.2121
\]

4. Finally, multiply by 100% to get the percent error:

\[
\text{Percent Error} \approx -0.2121 \times 100\% \approx -21.21\%
\]

Since we round to two decimal places, we can say:

\[
\text{Percent Error} \approx -21\%
\]

Therefore, the percent error of Simon's estimate is approximately **−21%**.

The correct response is **−21%**.