7.5 percent of decrease 2

Daily Homework Quiz For use after Lesson 7.4

Write the decimal or fraction as a percent.

1. 6.527 50

2.


Write the decimal or fraction as a percent.

1. 6.527 50

2.

ANSWER 650% ANSWER 54%

Percent of Change7.5

Applications of Percents

Real Life Situations

Percent of Change

Most of the time our setup will be:

%

100

Amount of change of change

original

GUIDED PRACTICE for Examples 1, 2 and 3

Tell whether the change is an increase or decrease. Then find the percent of change. Round to the nearest percent.

1. Original amt = 50New amt = 36

The change is a decrease since the new amount is less than the original amount

14 50

= x

100

50x 14( 100)=

50x 1,400=50 50

x = 28%

2. Original amt = 10New amt = 29.5

The change is an increase since the new amount is greater than the original amount

GUIDED PRACTICE for Examples 1, 2 and 3

Tell whether the change is an increase or decrease. Then find the percent of change. Round to the nearest percent.

19.5 10

= x

100

10x 19.5( 100)=

10x 1,950=10 10

x = 195%


Use the percent of change equation to find the new amount.

1. a goose population of 25 increases 20%. What is the new population?

ANSWER 25 + 5 = 30 geese

x 25

= 20

100

100x 25( 20)=

100x 500=100 100

x = 5

x 25

= 120

100

100x 25( 120)=

100x 3,000=100 100

x = 30



2. a bank balance of $500 decreases 60%.

What is new amount in the bank account?

ANSWER $500 – $300 = $200

x 500

= 60

100

100x 60( 500)=

100x 30,000=100 100

x = 300

x 500

= 40

100

100x 40( 500)=

100x 20,000=100 100

x = $200



3. a dieter’s weight of 180 pounds decreases 5%.

What is the dieter’s new weight?

ANSWER 180 – 9 = 171 lb

x 180

= 5

100

100x 5( 180)=

100x 900=100 100

x = 9

x 180

= 95

100

100x 95( 180)=

100x 17,100=100 100

x = 171

Homework

• Page 368 #1-12, 27-28– Your assignment will be graded as follows:

• 1 point for your proportion• 1 point for your answer

%

100

Amount of change of change

original

7.5 percent of decrease 2

Business