Proportions Review

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. You can find the missing value by rearranging this equation.

Front

If a recipe calls for 2 cups of sugar for every 3 cups of flour, how much sugar is needed for 9 cups of flour?

Back

6 cups of sugar.

Front

What is a ratio?

Back

A ratio is a comparison of two quantities, showing how many times one value contains or is contained within the other.

Front

How can you tell if two ratios form a proportion?

Back

Two ratios form a proportion if their cross products are equal.

Front

If 4 out of 5 students prefer chocolate ice cream, how many students out of 25 would you expect to prefer chocolate?

Back

20 students.

Front

What is the relationship between ratios and fractions?

Back

Ratios can be expressed as fractions, where the first quantity is the numerator and the second quantity is the denominator.

Front

If a car travels 150 miles on 5 gallons of gas, what is the car's miles per gallon?

Back

30 miles per gallon.

Front

What is the scale factor in a proportion?

Back

The scale factor is the ratio of any two corresponding lengths in two similar geometric figures.