## Video and Examples

Using ratios to make decisions. Sample problem here.

After the first dance of the school year, the student council set a goal to increase the rate of participation of boys at school dances. Here is how the first two dances were attended.

• Dance 1 --> 40 boys and 60 girls
• Dance 2 --> 50 boys and 100 girls

Is the student council successful in increasing the rate of participation of the boys at school dances?

There are three common methods for answering this question:

 Method 1: Ratios with common denominators Since , the rate of the boys' participation is declining, so the council has NOT met their goal. Method 2: Unit ratios Since , the rate of the boys' participation is declining, so the council has NOT met their goal. Method 3: Ratios with common numerators Since , the rate of the boys' participation is declining, so the council has NOT met their goal.

 Example 1 Which store has the better dealâ€Œ? Store A sells 4 baseballs for $3. Store B sells 5 baseballs for$4. Here is one method for solving this question...

 Example 2 Whose raffle tickets cost the least? Jamie sells 5 raffle tickets for $10. Patty sells 10 raffle tickets for$15. Here is one method for solving this question...

 Example 3 Which store has the better deal? Store A sells 12 batteries for $5.28. Store B sells 10 batteries for$4.50. [show answer]   Here is one method for solving this question...

# Self-Check

 Question 1 Who hit the most homeruns per game? Barry hit 15 homeruns in 20 games. Sammy hit 12 homeruns in 15 games. [show answer] Using common denominators... Barry: $\frac{15}{20}=\frac{45}{60}$ Sammy: $\frac{12}{15}=\frac{48}{60}$ Sammy hits more homeruns per game.

 Question 2 Which jar of peanut butter is the better deal? SmartShopper sells 24 ounces for $4.50 GroceryMania sells 30 ounces for$6.00 [show answer] Using common denominators... SS: $\frac{24}{4.5}=\frac{96}{18}$ GM: $\frac{30}{6}=\frac{90}{18}$ SmartShopper is the better deal since 96 ounces for \$18 is better than 90 ounces for the same price.

 Question 3 Who ran at a faster pace? Lisa ran 9 laps in 15 minutes. Jennifer ran 12 laps in 25 minutes. [show answer] Using common denominators... Lisa: $\frac{9}{15}=\frac{45}{75}$ Jennifer: $\frac{12}{25}=\frac{36}{75}$ Lisa ran faster.