Proportions Simple

Front

What is a proportion?

Back

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

Front

If a/b = c/d, what is the cross-multiplication rule?

Back

The cross-multiplication rule states that a * d = b * c.

Front

Solve the proportion: 3/4 = x/12

Back

x = 9.

Front

What does it mean if two ratios are in proportion?

Back

It means that the two ratios express the same relationship between their quantities.

Front

Solve the proportion: 5/x = 15/45

Back

x = 3.

Front

What is the first step in solving a proportion?

Back

Identify the two ratios and set them equal to each other.

Front

Solve the proportion: 8/10 = x/25

Back

x = 20.

Front

What is the term for the number that makes a proportion true?

Back

It is called the 'mean' or 'cross product'.

Front

Solve the proportion: 7/14 = x/28

Back

x = 14.

Front

What is the relationship between the means and extremes in a proportion?

Back

In a proportion a/b = c/d, the means are b and c, and the extremes are a and d.