Proportions

Front

What is a proportion?

Back

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

Front

How do you solve a proportion?

Back

To solve a proportion, cross-multiply the two ratios and set the products equal to each other.

Front

What is the formula for finding a missing value in a proportion?

Back

If a/b = c/d, then ad = bc.

Front

If 12 ounces of shampoo lasts 16 weeks, how long will 18 ounces last?

Back

24 weeks.

Front

What is a ratio?

Back

A ratio is a comparison of two quantities by division.

Front

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

Back

8 girls.

Front

What is the relationship between ratios and proportions?

Back

Ratios compare two quantities, while proportions state that two ratios are equal.

Front

If a grading machine can grade 48 tests in 1 minute, how long will it take to grade 288 tests?

Back

6 minutes.

Front

How do you find the total number of items in a ratio?

Back

Add the parts of the ratio together to find the total.

Front

If a park ranger stocks a pond with a ratio of 4 sunfish to 3 perch, how many perch are needed for 300 sunfish?

Back

225 perch.