​The ratios of the paint needs to be proportional, so we can set up a proportion.

​x = 16

16 quarts of Ruby Red paint​

In an animal shelter, the ratio of dogs to cats is 5 to 7. There are 25 dogs. Write a proportion and use proportional reasoning to find the total number of animals.

Let's write the proportion in words first.

Dogs

Cats

The ratio of dogs to cats is 5 to 7. There are 25 dogs. Write and solve a proportion to find the total number of animals

Now let's fill in the numbers.

Dogs = 5

Cats 7

the ratio of dogs to cats is 5 to 7. There are 25 dogs. Write and solve a proportion to find the total number of animals

Now we need to set up a proportion​

the ratio of dogs to cats is 5 to 7. There are 25 dogs. Write and solve a proportion to find the total number of animals

​

​We ask ourself: "How did I get from 5 to 25?"

MULTIPLY BY 5​

​If you multiply the numerators by 5, you have to multiply the denominator by 5

BUT.........​

​

​THE QUESTION ASKS:

​

​WHAT IS THE TOTAL NUMBER OF ANIMALS?????

​25 DOGS + 35 CATS = 60 ANIMALS

In an exercise class, the ratio of men to women is 3:4. If there are 21 men, how many women are in the exercise class?

Set up a proportion of men over women.​

In an exercise class, the ratio of men to women is 3:4. If there are 21 men, how many women are in the exercise class?

In an exercise class, the ratio of men to women is 3:4. If there are 21 men, how many women are in the exercise class?

​There are 28 women in the class.

The ratio of boys to girls is 3 to 2. If there are 12 boys, how many girls are there?