6.2 Students will use proportions to solve percentage problems.Warm Up
Rewrite each value as indicated.
1. as a percent
2. 25% as a fraction
3. as a decimal
4. 0.16 as a fraction
48%
0.375
425
24 50
3 8
14
6.2 Students will use proportions to solve percentage problems.
General ObjectiveStudents will use proportions to solve
percentage problems.
6.2 Students will use proportions to solve percentage problems.
The Percent Proportion
=number
100 part Whole (of)
12 is what % of 40?
6.2 Students will use proportions to solve percentage problems.
What percent of 92 is 66?
Example 1: Finding the Percent One Number Is of Another
Think: What number is to 100 as 66 is to 92?
=number
100 partwhole
Set up a proportion.
Substitute. n
100 6692
=
n 92 = 100 66
92n = 6600
Find the cross products.
Method 1: Set up a proportion to find the percent.
Simplify.
6.2 Students will use proportions to solve percentage problems. Additional Example 1 Continued
n ≈ 72
Divide both sides by 92.
66 is approximately 72% of 92.
Simplify.
92n = 6600 92 92
6.2 Students will use proportions to solve percentage problems.
What percent of 140 is 21?
Think: What number is to 100 as 21 is to 140?
=number
100 partwhole Set up a proportion.
Let n represent the percent. n
100 21140
=
n 140 = 100 21
140n = 2100
Find the cross products.
Try It! Example 1
Method 1: Set up a proportion.
Simplify.
6.2 Students will use proportions to solve percentage problems.
n = 15
Divide both sides by 140.
21 is 15% of 140.
Try It! Example 1 Continued
Simplify.
140n = 2100 140 140
6.2 Students will use proportions to solve percentage problems.Practice: Green: 1, 3 Red: 2, 5 Blue: 3, 4
1. What percent of 80 is 20?
2. What percent of 48 is 16?
3. 300 out of 1000 is what percent?
4. 70 is what percent of 35?
5. A bin contains 120 ears of white and yellow corn. Of these, 78 ears are yellow. What percent of the ears of corn are yellow? What percent are white?
25%
33 1/3%
30%
200%
65%; 35%
6.2 Students will use proportions to solve percentage problems.
Lesson Quiz: Part
Find each percent.
1. What percent of 75 is 15? 20%
6.2 Students will use proportions to solve percentage problems.
1. What percent of 75 is 15?
A. 5
B. 10
C. 20
D. 50
Lesson Quiz for Student Response Systems
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