1. Write Ratios & Proportions Section 3.5 P. 162-167
2. • We will review the concept of a ratio and a proportion.• We will solve proportions algebraically.• We will relate proportions to real-world situations.
3. • What is a ratio? A ratio uses division to compare two quantities.• How can ratios be written? a to b a:b a bAll the above are read “ a to b.”Ratios should be written in simplest form.
4. • A volleyball team plays 14 home matches and 10 away matches.• Find the ratio of home matches to away matches.• Find the ratio of home matches to all matches.• Find the ratio of away to home matches.• Write your answer in simplest form.
5. • What is a proportion?• A proportion is an equation that states that two ratios are equivalent. a c , where b, d 0 b d
6. • Many times one of the values of a proportion is unknown. You can solve a proportion using the same methods you used to solve equations.• Some proportions can also be solved by the concept of equivalent ratios.
7. Setting up a proportion• 3 is to 8 as x is to 32 solve for “x”• y is to 10 as 7 is to 2 solve for “y”
8. w 435 7
9. 36 x 72 10Hint: may need to simplify ratio first.
10. r 90.5 2.5
11. • A printer can print 12 color pages in 3 minutes. How many color pages can the printer print in 9 minutes?• Write a proportion and solve.
12. • One day, the ratio of skiers to snowboarders on the mountain at a ski resort was 13:10. The resort sold a total of 253 lift tickets during the day.• Find the ratio of snowboarders to all the skiers and snowboarders.• Use the ratio to find the number of lift tickets sold to snowboarders during the day.
13. • Assignment: P. 165 (#2-30 evens only) Copy the problems