Answer: 25%
Explanation:
Given : Roger has a nail that is 12 centimeters long.
He measures and records the length of the nail as 15 centimeters.
i.e. Estimated length = 15 cm and Actual length = 12 cm
The percent error in Rogers measurements is given by :-
![\frac{|\text{Estimated-Actual}|}{\text{Actual}}*100\\\\=(|12-15|)/(12)*100\\\\=(3)/(12)*100=25\%](https://img.qammunity.org/2019/formulas/mathematics/middle-school/27p0rqhakdf6k4xi5ht8j14u7at9sr6zn3.png)
Hence, the percent error in Rogers measurements is 25%.