Using Equivalent Ratios EXAMPLE 1 Sports A person burned about 210 calories while in-line skating for 30 minutes. About how many calories would the person burn while in-line skating for 60 minutes? In example 1, you will use a proportion to answer this question.
EXAMPLE 1 Find the number C of calories the person discussed would burn while in-line skating for 60 minutes by solving the proportion c 60 = SOLUTION STEP 1 Ask yourself: What number can you multiply 30 by to get 60? c 60 = Using Equivalent Ratios
EXAMPLE 1 STEP 2 Because multiply the numerator by 2 to find C = c 60 = ANSWER Because = 420, C = 420. So, the person would burn about 420 calories while in-line skating for 60 minutes. Using Equivalent Ratios
Solving Proportions Using Algebra EXAMPLE 2 Solve the proportion 6 10 x 25 = 6 10 x 25 = Write original proportion. x = 25 Multiply each side by = x 15 = x Simplify fraction. Simplify. ANSWER The solution is 15.
Use equivalent ratios to solve the proportion. GUIDED PRACTICE for Examples 1 and z 20 = 1. ANSWER k 18 = 2. ANSWER c 9 12 = 3. ANSWER 36 9 n = 4. ANSWER 2
GUIDED PRACTICE for Examples 1 and m 49 = 5. Use algebra to solve the proportion. ANSWER x 12 = 6. ANSWER 10 h = 7. ANSWER 11 b = 8. ANSWER 2