Chapter 2 - Solving Equations - 2-10 Change Expressed as a Percent - Practice and Problem-Solving Exercises - Page 148: 19

13%

The equation for percent error is the following: $(\frac{estimated value - actual value}{actual value})\times100$ Thus, we plug in the numbers to find: $(\frac{45-52}{52})\times100\approx13$%. Note, a percent error is always positive. Thus, we make our answer positive.