Exercise 3 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 80% of 60 is by thinking about 80 as the percent and 60 as the whole. Let's substitute p= 80 and w= 60 into the formula and solve for a using the Properties of Equality.

a/w=p/100

SubstituteII

p= 80, w= 60

a/60=80/100

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Solve for a

MultEqn

LHS * 60=RHS* 60

a/60* 60=80/100 * 60

FracMultDenomToNumber

a/60* 60 = a

a=80/100 * 60

MoveRightFacToNum

a/c* b = a* b/c

a=80* 60/100

Multiply

Multiply

a=4800/100

CalcQuot

Calculate quotient

a= 48

Knowing the value of a, let's look at the completed percent proportion. 48/60=80/100 We found that 48 is 80 % of 60.

Checking Our Answer

Checking Our Answer

We can use a model to check our answer.