Exercise 29 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 25% of 78 is by thinking about 25 as the percent and 78 as the whole. Let's substitute p= 25 and w= 78 into the formula and solve for a using the Properties of Equality.

a/w=p/100

SubstituteII

p= 25, w= 7/8

a/78=25/100

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Solve for a

MultEqn

LHS * 7/8=RHS* 7/8

a/78* 7/8=25/100 * 7/8

FracMultDenomToNumber

a/7/8* 7/8 = a

a=25/100 * 7/8

MultFrac

Multiply fractions

a=25* 7/100* 8

Multiply

Multiply

a=175/800

ReduceFrac

a/b=.a /25./.b /25.

a=175÷ 25/800÷ 25

CalcQuot

Calculate quotient

a= 7/32

Knowing the value of a, let's look at the completed percent proportion. 732/78=25/100 We found that 732 is 25 % of 78.