Exercise 2 Page 251

The percent proportion is a proportion that sets the ratio of a part of a whole equal to the ratio of a percent out of 100. We can represent a is p percent of wwith the given proportion. part/whole=percent/100 ⇔ a/w=p/100We can find what percent 42 of 80 is by thinking about 42 as the part of a whole and 80 as the whole. Let's substitute a= 42 and w= 80 into the formula and solve for p using the Properties of Equality.

Knowing the value of p, let's look at the completed percent proportion. 42/80=52.5/100 We found that 42 is 52.5 % of 80.