Proportions

Front

What is a proportion?

Back

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

Front

How can 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 \( \frac{a}{b} \) and \( \frac{c}{d} \)?

Back

The cross product is \( a \times d \) and \( b \times c \). If \( a \times d = b \times c \), then the ratios are proportional.

Front

If 6 red cars are sold for every 3 blue cars, what is the simplified ratio?

Back

The simplified ratio is 2 red cars for every 1 blue car.

Front

If \( \frac{2x}{20} = \frac{2}{4} \), what is the value of x?

Back

x = 5.

Front

If 2 apples cost $20, how much do 5 apples cost?

Back

5 apples cost $50.

Front

What is the relationship between equivalent ratios?

Back

Equivalent ratios represent the same relationship between quantities.

Front

How do you write a ratio?

Back

A ratio can be written as a fraction, with a colon, or with the word 'to' (e.g., 2:3, \( \frac{2}{3} \), or '2 to 3').

Front

What does it mean if two ratios are not a proportion?

Back

It means that the cross products of the ratios are not equal.

Front

What is an example of a proportion?

Back

An example of a proportion is \( \frac{1}{2} = \frac{2}{4} \).