1. Solving Percent Problems Using Proportions
COURSE 2 LESSON 6-5
117 is 45% of what number?
The model shows the relationship. =
117 n 45
100
Write the proportion.
Write the cross products.
45n = 117(100)
Divide each side by 45.
45n 45
117(100) =
n = 260
Simplify.
117 is 45% of 260.
6-5

2. Solving Percent Problems Using Proportions
COURSE 2 LESSON 6-5
Use a proportion to solve: 96 is 15% of what number? Model the relationship.
The model shows the relationship. = 96 n 15
100
Write the proportion.
Write the cross products.
15n = 96(100)
Divide each side by 15.
15n 15
96(100) =
n = 640
Simplify.
Check 15% of 640 = 0.15 • 640 = 96 
6-5

3. Solving Percent Problems Using Proportions
COURSE 2 LESSON 6-5
Use a proportion to solve.
1. What percent of 240 is 60? is what percent of 120?
3. 75% of what number is 66? is 96% of what number?
25%
75% 88 25
6-5