ratios and proportions

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

What is a proportion?

Back

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

Front

How do you determine if two ratios form a proportion?

Back

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

Front

What is the cross product of the ratios a/b and c/d?

Back

The cross product is ad and bc. If ad = bc, then the ratios a/b and c/d are proportional.

Front

If 2/3 = x/9, what is the value of x?

Back

x = 6.

Front

What does it mean for a relationship to be proportional?

Back

A relationship is proportional if it can be expressed as a constant ratio.

Front

How can you tell if a table shows a proportional relationship?

Back

A table shows a proportional relationship if the ratios of corresponding values are equal.

Front

If a 12 pack of soda costs $3.50, what is the cost per can?

Back

The cost per can is $0.29.

Front

If 5/8 = x/32, what is the value of x?

Back

x = 20.

Front

What is the unit rate?

Back

The unit rate is a comparison of two different quantities when they are combined into a single unit.