Intro to Proportions

Front

What is a proportion?

Back

A proportion is an equation that states that two ratios are equal.

Front

How do you set up a proportion?

Back

To set up a proportion, you can use the formula a/b = c/d, where a and b are the first ratio, and c and d are the second ratio.

Front

What does it mean to solve a proportion?

Back

Solving a proportion means finding the unknown value in the ratio that makes the two ratios equal.

Front

If 14 out of 50 fish are trout, what is the ratio of trout to total fish?

Back

The ratio of trout to total fish is 14:50, which simplifies to 7:25.

Front

How do you find the expected number of items using a proportion?

Back

To find the expected number, set up a proportion based on the known ratio and solve for the unknown.

Front

What is the expected number of trout in a lake with a population of 7,500 if 14 out of 50 fish are trout?

Back

The expected number of trout is 2,100.

Front

If 13 out of 20 homes have a personal computer, what is the ratio of homes with computers?

Back

The ratio is 13:20.

Front

How many homes would you expect to have a personal computer on a street with 60 homes?

Back

You would expect 39 homes to have a personal computer.

Front

What is the ratio of dogs to cats in an animal shelter if there are 25 dogs and the ratio is 5:3?

Back

The ratio of dogs to cats is 5:3, so there are 15 cats.

Front

How do you write a proportion to find the number of cats if there are 25 dogs?

Back

Set up the proportion 5/3 = 25/c and solve for c.