Chapter 4 - Proportions, Percents, and Solving Inequalities - 4.2 - Percents and Problem Solving - Problem Set 4.2 - Page 155: 29

The answer is 7.5%.

Let X be the number we are looking for. 16.5 is means 16.5= What percent of 220 means X $\times$ 220. So, this question translates to: 16.5 = X $\times$ 220 Divide both sides by 220 X = 0.075 To turn 0.075 into a percentage, we multiply it by 100%. So, 0.075 $\times$ 100% = 7.5%