0-6: THE PERCENT PROPORTION

0-6: The Percent Proportion

Percent: A ratio that compares numbers to 100.

To write a percent as a fraction: Write the ratio with a denominator of 100 Simplify the fraction, if possible

Examples 79%

107%

0.5%

79

100

107

100

0.5

100

5

1000

1

200

0-6: The Percent Proportion

Percent proportion: A ratio of part to a whole equal to a percentage. part percentage

whole Is/Of = Percent/100

Example 2 (find the part) 40% of 30 is what number?

Fill in known information

Cross-multiply 100a = 1200 Divide by 100 a = 12

100

a p

b

4

30 00

0

1

a

0-6: The Percent Proportion

Example 3 (find the percentage): Kelsey took a survey of students in her lunch period. 42 out of the 70 students surveyed said their family had a pet. What percent of the students had pets?

Fill in known information Cross-multiply: 4200 = 70p Divide by 70 p = 60

So 60% of the students had pet

0

42

70 10

p

0-6: The Percent Proportion

Example 4 (Find the whole) 67.5 is 75% of what number?

Fill in known information Cross-multiply: 6750 = 75b Divide by

75 90 = b

6

100

7.5 75

b

0-6: The Percent Proportion

What is 35% of 250? 87.5

17 is what percent of 68? 25%

Thirty percent of a number is 39. Find the number. 130

Rudy went to see a baseball game. While keeping stats, he counted 44 at bats for the home team. Of these, 11 batters made a hit. What percent of batters got a hit for the home team? 25%

0-6: The Percent Proportion

Assignment Pages P21-P22 Problems 1 – 31 (odds)