Exercise 8 Page 243

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 60% of 30 is by thinking about 60 as the percent and 30 as the whole. Let's substitute p= 60 and w= 30 into the formula and solve for a using the Properties of Equality.

a/w=p/100

SubstituteII

p= 60, w= 30

a/30=60/100

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Solve for a

MultEqn

LHS * 30=RHS* 30

a/30* 30=60/100 * 30

FracMultDenomToNumber

a/30* 30 = a

a=60/100 * 30

MoveRightFacToNum

a/c* b = a* b/c

a=60* 30/100

Multiply

Multiply

a=1800/100

CalcQuot

Calculate quotient

a= 18

Knowing the value of a, let's look at the completed percent proportion. 18/30=60/100 We found that 18 is 60 % of 30.

Checking Our Answer

Checking Our Answer

We can use a model to check our answer.