Page 190 - Math Course 1 (Book 1)

Percent Proportion

Mo. 6

Lesson 4

KEY CONCEPTS: Concept Summary
1. Using the percent proportion to solve
problems. Type of Percent Proportion

Type Example Proportion

3 is what percent
MO. 6 - L4a Find the of 4? or What 3 = n
Percent 4 100
percent of 4 is 3?
Problem Soving: Using Find the What number is n = 75

Percent Proportions Part 75% of 4? 4 100

Find the 3 is 75% of what 3 75
Vocabulary A-Z whole number? n = 100

Let us learn some vocabulary

Percent Proportion
Let’s Begin
In a percent proportion, one ratio compares part of a
quantity to the whole quantity, also called the base,
as a fraction.

The other ratio is the equivalent percent written as a Find the Percent
fraction with a denominator of 100.

Part 3 75 Examples
= Percent
whole 4 100 Twenty is what percent of 25?
3 out of 4 is 75%
Twenty is being compared to 25. So, 20 is the
part and 25 is the whole. Let n represent the
percent.

Key Concept 20 = n Write the percent proportion.
25 100
22 • 100 = 25 • n Find the cross products.
Percent Proportion 2000 = 25n Simplify

Words part = percent 2000 = 25n Divide each side by 25.
whole 100 25 25

a p 80 = n Simplify.
Symbol = , where a is part, b is the
b 100
whole base or base, and p is the percent.
Answer 20 is 80% of 25.

182