MY NOTES ASK YOUR TEACHER percent of change is the percent that a quantity changes from the original amount. When the original amount increases, the percent of change is called a percent of increase and can be alculated using the formula Percent of Increase - new amount original amount original amount (a) What is the percent of increase from 60 to 84? % (b) A class size increases from 23 students to 28 students. Calculate the percent of increase. Round your answer to the nearest tenth of a percent. %