Exercise 26 Page 246

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 0.5 of 20 is by thinking about 0.5 as the part of a whole and 20 as the whole. Let's substitute a= 0.5 and w= 20 into the formula and solve for p using the Properties of Equality.

a/w=p/100

SubstituteII

a= 0.5, w= 20

0.5/20=p/100

▼

Solve for p

MultEqn

LHS * 100=RHS* 100

0.5/20* 100=p/100 * 100

FracMultDenomToNumber

a/100* 100 = a

0.5/20* 100=p

MoveRightFacToNum

a/c* b = a* b/c

0.5* 100/20=p

Multiply

Multiply

50/20=p

CalcQuot

Calculate quotient

2.5=p

RearrangeEqn

Rearrange equation

p= 2.5

Knowing the value of p, let's look at the completed percent proportion. 0.5/20=2.5/100 We found that 0.5 is 2.5 % of 20.