Exercise 5 Page 125

Let's start by recalling that 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. part/whole=percent/100 We want to find what percent of 50 is 18. Let n represent the percent. 18/50=n/100 Now we can solve the proportion we got for n. Let's do this by using the fact that the cross products of any proportion are equal.

18/50=n/100

CrossMult

Cross multiply

18* 100= 50 * n

Multiply

Multiply

1800=50n

Finally, we will use the Division Property of Equality to get the value of n.

1800=50n

DivEqn

.LHS /50.=.RHS /50.

1800/50=50n/50

CancelCommonFac

Cancel out common factors

1800/50=50n/50

SimpQuot

Simplify quotient

1800/50 = n

CalcQuot

Calculate quotient

36 = n

RearrangeEqn

Rearrange equation

n = 36

We got that n= 36 is a solution to the proportion. This means that 18 is 36 % of 50.