Question

The baker estimated a total of 105 minutes to decorate the 3 layer cake. It actually took him a little longer and he finished decorating the cake in 126 minutes. What is the baker's percent error? Round your answer to the nearest tenth.

Answer 1

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

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

In this case, the Estimated Value is 105 minutes, and the Actual Value is 126 minutes.

Now we can plug in the values:

\[
\text{Percent Error} = \left( \frac{126 - 105}{105} \right) \times 100
\]

Calculating the numerator:

\[
126 - 105 = 21
\]

Now, substitute this back into the formula:

\[
\text{Percent Error} = \left( \frac{21}{105} \right) \times 100
\]

Now, calculating \(\frac{21}{105}\):

\[
\frac{21}{105} = 0.2
\]

Finally, multiplying by 100 to convert to a percentage:

\[
0.2 \times 100 = 20
\]

Thus, the baker's percent error is:

\[
\boxed{20.0}
\]