exercise 30% 15 50 express the ratio as a percent

ExerciseExercise

30%30%

15501550

Express the ratio as a percent.Express the ratio as a percent.

25%25%

15601560

Express the ratio as a percent.Express the ratio as a percent.

ExerciseExercise

3030

What is 60% of 50?What is 60% of 50?ExerciseExercise

60% of what number is 150?60% of what number is 150?250250

ExerciseExercise

What percent of 50 is 150?What percent of 50 is 150?300%300%

ExerciseExercise

Determine next year’s sales goal, N, if the company wants to increase this year’s sales of $250,000 by 15%.

Determine next year’s sales goal, N, if the company wants to increase this year’s sales of $250,000 by 15%.

N = $287,500N = $287,500

The goal is 115% of last year’s sales.

The goal is 115% of last year’s sales.

N = 1.15(250,000)N = 1.15(250,000)

Example 1Example 1

Percent Change FormulaPercent Change Formula

percent change =percent change =amount of changeoriginal amount

amount of changeoriginal amount

x 100%x 100%

Finding the Percent Change

Finding the Percent Change

1. Subtract to find the amount of change.

2. Divide the amount of change by the original amount.

Finding the Percent Change

Finding the Percent Change

3. Convert the quotient to a percent and indicate whether it is an increase or a decrease.

What is the percent change from 75 to 100?What is the percent change from 75 to 100?

100 – 75 = 25100 – 75 = 25changeoriginalchangeoriginal

25752575

== = 0.3= 0.3

The percent change is a 33.3% increase.

The percent change is a 33.3% increase.

Example 2Example 2

Find the percent change. Round to the nearest whole percent.

Find the percent change. Round to the nearest whole percent.

29%29%

original amount: 42new amount: 54

original amount: 42new amount: 54

ExampleExample

Find the percent change. Round to the nearest whole percent.

Find the percent change. Round to the nearest whole percent.

49%49%

original amount: 150new amount: 224

original amount: 150new amount: 224

ExampleExample

Find the percent change. Round to the nearest whole percent.

Find the percent change. Round to the nearest whole percent.

17%17%

original amount: 1,080new amount: 900

original amount: 1,080new amount: 900

ExampleExample

Find the percent change, to the nearest whole percent, from 19 to 16. Indicate whether it is an increase or a decrease.

Find the percent change, to the nearest whole percent, from 19 to 16. Indicate whether it is an increase or a decrease.19 – 16 = 319 – 16 = 33

193

19≈ 0.16≈ 0.16 = 16% decrease = 16% decrease

Example 3Example 3

Find the percent change from 2,400 to 2,650. Indicate whether it is an increase or decrease. Round to the nearest whole percent.

Find the percent change from 2,400 to 2,650. Indicate whether it is an increase or decrease. Round to the nearest whole percent.

10% increase10% increase

ExampleExample

Find the percent change from 13 to 18. Indicate whether it is an increase or decrease. Round to the nearest whole percent.

Find the percent change from 13 to 18. Indicate whether it is an increase or decrease. Round to the nearest whole percent.

38% increase38% increase

ExampleExample

Find the percent change from 144 to 120. Indicate whether it is an increase or decrease. Round to the nearest whole percent.

Find the percent change from 144 to 120. Indicate whether it is an increase or decrease. Round to the nearest whole percent.

17% decrease17% decrease

ExampleExample

Last year Mrs. Rutherford’s homeroom sold 56 cartons of candy bars. This year her homeroom sold 80 cartons. What was the percent change? Give the answer to the nearest tenth of a percent.

Last year Mrs. Rutherford’s homeroom sold 56 cartons of candy bars. This year her homeroom sold 80 cartons. What was the percent change? Give the answer to the nearest tenth of a percent.

Example 4Example 4

Last year Mrs. Rutherford’s homeroom sold 56 cartons of candy bars. This year her homeroom sold 80 cartons.

Last year Mrs. Rutherford’s homeroom sold 56 cartons of candy bars. This year her homeroom sold 80 cartons.

= 42.9% increase= 42.9% increase

24562456 ≈ 0.429≈ 0.429

80 – 56 = 2480 – 56 = 24

Dillon has 65 baseball cards and Joseph has 50. Dillon has what percent more than Joseph? Joseph has what percent less than Dillon?

Dillon has 65 baseball cards and Joseph has 50. Dillon has what percent more than Joseph? Joseph has what percent less than Dillon?

65 – 50 = 1565 – 50 = 15

Example 5Example 5

Dillon has 65 baseball cards and Joseph has 50. Dillon has 65 baseball cards and Joseph has 50.

Dillon has 30% more cards than Joseph. Joseph has

23% less than Dillon.

Dillon has 30% more cards than Joseph. Joseph has

23% less than Dillon.

15501550

= 30%= 30%

3010030

100== 15

651565

≈ 0.23≈ 0.23

= 23%= 23%

Find the percent change in the following problems. Indicate whether it is an increase or a decrease. Round to the nearest whole percent.

Find the percent change in the following problems. Indicate whether it is an increase or a decrease. Round to the nearest whole percent.

ExampleExample

Caleb earned $225 per week waiting on tables at a restaurant last summer. This year he earned $305 per week.

Caleb earned $225 per week waiting on tables at a restaurant last summer. This year he earned $305 per week. 36% increase36% increase

ExampleExample

A couple bought a new car for $18,995 three years ago. They just sold it for $8,000.

A couple bought a new car for $18,995 three years ago. They just sold it for $8,000.

58% decrease58% decrease

ExampleExample

Mr. Fremont’s homeroom brought in 14,000 lb. of nonperishables last year in the food drive. This year they brought in 16,500 lb.

Mr. Fremont’s homeroom brought in 14,000 lb. of nonperishables last year in the food drive. This year they brought in 16,500 lb.

18% increase18% increase

ExampleExample

Seth bought a guitar on sale for $250. It had been reduced from $290.

Seth bought a guitar on sale for $250. It had been reduced from $290. 14% decrease14% decrease

ExampleExample