Ratios and Proportions Review

Front

What is a ratio?

Back

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

Front

What does it mean for two ratios to be proportional?

Back

Two ratios are proportional if they express the same relationship between their quantities, meaning they can be set equal to each other.

Front

How do you find a unit rate?

Back

To find a unit rate, divide the first quantity by the second quantity to determine how much of the first quantity corresponds to one unit of the second quantity.

Front

If a ratio of dogs to cats is 5:3 and there are 25 dogs, how many cats are there?

Back

c = 15 (using the proportion 5/3 = 25/c).

Front

What is the unit rate of 405 rotations in 5 minutes?

Back

81 rotations per minute (405 ÷ 5 = 81).

Front

How do you set up a proportion?

Back

A proportion is set up by creating an equation that states two ratios are equal, often using cross-multiplication to solve.

Front

What is the scale of a drawing?

Back

The scale of a drawing is the ratio of the dimensions in the drawing to the actual dimensions of the object.

Front

If a 12-ounce bottle of shampoo lasts 16 weeks, how long will an 18-ounce bottle last?

Back

24 weeks (using the ratio of ounces to weeks).

Front

What is the formula for finding the actual length from a scale drawing?

Back

Actual Length = (Length in Drawing) × (Actual Scale Factor).

Front

What is a proportion?

Back

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