Download 5.1 Ratio and Proportion Learning Objectives: 1. Write

5.1 Ratio and Proportion Learning Objectives: 1. Write ratios as fractions. 2. Write rates as fractions and find unit rates. 3. Determine whether proportions are true. 4. Find an unknown number in a proportion. 5. Solve problems by writing proportions. 1. Write ratios as fractions Ratio—is the quotient of two quantities. Three ways to write a ratio: a
1. a to b 2. 3. a : b b
Example 1. Write each ratio as a fraction in simplest form. 1. 6.6 miles to 10 miles 2. Write rates as fractions and find unit rates Rates are used to compare different kinds of quantities. 6 tests for 30 students Example 2. Write each rate as a fraction in simplest form: 3. Determine whether proportions are true Proportion—is a statement that two ratios or rates are equal. Using Cross Products Rule to Determine Whether Proportions Are True or False Example 3. Determine whether each proportion is true or false. 8
2
8
2
9 = 9 1. 30
7
4. Finding Unknown Numbers in Proportions Example 4. Solve the proportion. 1
n
= 1. 1 19
9
2
4.5 2.5
2. =
x
5.5
5. Solve problems by writing proportions Example 6. Use proportion to solve the following application. 1. The ratio of students to faculty is 25 to 2. How many faculty members will be needed for a student population of 625? ***************************************************************************************************** Read: Section 5.3/5.4