Question

A bakery sold 110 cupcakes in one day. The head baker predicted he would sell 90 cupcakes that day. What was the percent error of the baker's prediction?

Answer 1

To calculate the percent error of the baker's prediction, we can use the formula for percent error:

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

In this case:

- Actual Value (number of cupcakes sold) = 110
- Predicted Value (number of cupcakes predicted) = 90

Now, let's substitute these values into the formula:

\[
\text{Percent Error} = \left( \frac{110 - 90}{110} \right) \times 100
\]

Calculating the numerator:

\[
110 - 90 = 20
\]

Now, substituting this back into the formula:

\[
\text{Percent Error} = \left( \frac{20}{110} \right) \times 100
\]

Calculating \( \frac{20}{110} \):

\[
\frac{20}{110} \approx 0.1818
\]

Now, multiply by 100 to find the percent:

\[
0.1818 \times 100 \approx 18.18
\]

Therefore, the percent error of the baker's prediction is approximately \( \boxed{18.18} \% \).