Solving Proportions
EXAMPLE 1 Solve the proportion x =. Solving Proportions METHOD - Use equivalent ratios x = X 5 = 60, so x = 60. The solution is 60. ANSWER
GUIDED PRACTICE n = 1 n = 1. k = k = 2. ANSWER n = k = Solve the proportion using equivalent ratios.
GUIDED PRACTICE x = x 6 11 = 3. s = s 12 = 4. ANSWER Solve the proportion using equivalent ratios. 30 x 6 11 = 10 4 s 12 =
EXAMPLE 2 Boating: You are on a riverboat trip. You travel 5 miles in 3 hours. At that same rate, how long will it take you to travel 20 miles? SOLUTION Use a proportion. Let t represent the total time, in hours, of the 2 0 mile trip. Write a verbal model. Distance traveled Time traveled Total distance Total time = Substitute values. 5 mi 3 h 20 mi 12 h = Solving Using a Verbal Model Solve the proportion 5 mi 3 h 20 mi t h =
GUIDED PRACTICE 5.What If? In Example 2, suppose you travel 4 miles in 2 hours. At that same rate, how long will it take you to travel 20 miles? 4 mi 2 h 20 mi t h = ANSWER t = t = 10 h for Example 2
Proportions around us SCHOOL The ratio of boys to girls in history class is 4 to 5. How many girls are in the class if there are 12 boys in the class?
Proportions at work FACTORIES A factory produces 6 motorcycles in 9 hours. Write a proportion and solve it to find how many hours it takes to produce16 motorcycles.
Proportions at home COOKING A recipe that will make 3 pies calls for 7 cups of flour. Write a proportion and solve it to find how many pies can be made with 28 cups of flour.
Proportions in sports BASKETBALL The Lakewood Wildcats won 5 of their first 7 games this year. There are 28 games in the season. About how many games would you expect the Wildcats to win this season?