Exercise 3 Page 141

In the percent proportion, the ratio of the part a to the whole b is equal to the percent p written as a fraction. a/b=p/100 Given any two of these three variables, we can find the third one. In this exercise, we are given the values p= 35 and b= 80, and we are looking for the percent a.

a/b=p/100

SubstituteII

b= 80, p= 35

a/80=35/100

ReduceFrac

a/b=.a /5./.b /5.

a/80=7/20

MultEqn

LHS * 20=RHS* 20

20a/80=7

CalcQuot

Calculate quotient

a/4=7

MultEqn

LHS * 4=RHS* 4

a=28

This means that 28 is 35 % of 80.