Page 279 - Algebra 1

A percent statement can be set up as a proportion. One ratio compares the part of a quantity to the whole quantity. The other ratio is the percent rate written in the form of a ratio.
_part = percent rate whole
For example, 10% of 50 is 5 can be written as a proportion.
Part_5 _
Whole = 10 50 100
Using a Proportion
a. What number is 125% of 48? SOLUTION
Set up a proportion to find the percentage.
Percent
Example
2
Caution
When setting up a proportion, make sure you know which is the part and which is the whole.
c = 125 __
48 100 6000 = 100c
60 = c
60 is 125% of 48.
Write a proportion. Cross multiply.
Solve for c.
_5
Check 125%is4.So,(4)(48)=60.
b. 15 is what percent of 45 ? SOLUTION
Set up a proportion to find the percent.
_5
__ 15 = x
45 100 45x =1500 x = 33.3−
1 5 i s 3 3 _1 % o f 4 5 . 3
Write a proportion. Cross multiply.
Solve for x.
_1 _1 _1
Check 333% is 3. So, (3)(45) = 15.
Example
3
Application: Calculating Wages
Ana receives $1153.84 in gross earnings every two weeks. However, 28.07% of the gross earnings is removed for taxes and other deductions.
Using an equation, determine the net pay.
264 Saxon Algebra 1