Marcus signed his dog up for an obstacle race. He predicted it would take his dog 18 minutes to complete the obstacle course, but his dog finished in 15 minutes. What is the percent error?
The percent error can be calculated using the formula:
Percent Error = (|Predicted Value - Actual Value| / Actual Value) * 100
In this case, the predicted value is 18 minutes and the actual value is 15 minutes.
Percent Error = (|18 - 15| / 15) * 100
= (3 / 15) * 100
= 0.2 * 100
= 20%
Therefore, the percent error is 20%.