Proportions

Front

What is a proportion?

Back

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

Front

How do you write a proportion using a table of values?

Back

You can write a proportion by setting two ratios equal to each other, such as \( \frac{a}{b} = \frac{c}{d} \).

Front

If \( \frac{4}{5} = \frac{8}{x} \), what is the value of x?

Back

x = 10.

Front

What is the ratio of boys to girls if there are 12 boys and the ratio is 3 to 2?

Back

There are 8 girls.

Front

How do you determine if two ratios form a proportion?

Back

Two ratios form a proportion if their 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 \( a \cdot d \) and \( b \cdot c \).

Front

If 2.08/16 = d/8, what is the value of d?

Back

d = 1.04.

Front

What does it mean if two ratios are equivalent?

Back

It means they represent the same relationship or proportion.

Front

How can you solve for an unknown in a proportion?

Back

You can cross-multiply and then solve for the unknown.

Front

What is the first step in solving the proportion \( \frac{3}{4} = \frac{x}{12} \)?

Back

Cross-multiply to get \( 3 \cdot 12 = 4 \cdot x \).