Chapter 2 - Solving Equations - 2-10 Change Expressed as a Percent - Practice and Problem-Solving Exercises - Page 149: 26

24%

The new number is higher than the original number, so we use the equation for percent increase. The equation for percent increase is the following: $(\frac{new amount - original amount}{original amount})\times100$ Thus, we plug in the numbers to find: $(\frac{22.25-18}{18})\times100\approx24$%