Exercise 22 Page 245

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 72 of 45 is by thinking about 72 as the part of a whole and 45 as the whole. Let's substitute a= 72 and w= 45 into the formula and solve for p using the Properties of Equality.

a/w=p/100

SubstituteII

a= 72, w= 45

72/45=p/100

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Solve for p

MultEqn

LHS * 100=RHS* 100

72/45* 100=p/100 * 100

FracMultDenomToNumber

a/100* 100 = a

72/45* 100=p

MoveRightFacToNum

a/c* b = a* b/c

72* 100/45=p

Multiply

Multiply

7200/45=p

CalcQuot

Calculate quotient

160=p

RearrangeEqn

Rearrange equation

p= 160

Knowing the value of p, let's look at the completed percent proportion. 72/45=160/100 We found that 72 is 160 % of 45.

Checking Our Answer

Checking Our Answer

We can use a model to check our answer.