Proportions

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 are proportional?

Back

Two ratios are proportional if their cross products are equal.

Front

What is the cross product of the ratios 7:12 and 5:8?

Back

The cross products are 7 * 8 = 56 and 12 * 5 = 60. Since 56 ≠ 60, they are not proportional.

Front

If 4.5 is 7.5% of what number, how do you find that number?

Back

To find the number, divide 4.5 by 0.075. The answer is 60.

Front

What is the formula for solving proportions?

Back

If a/b = c/d, then ad = bc.

Front

Solve for x: 3/4 = x/16

Back

x = 12.

Front

What does it mean if two ratios are not proportional?

Back

It means that the ratios do not represent the same relationship or scale.

Front

How can you check if x = 6 is a solution for the proportion 2/3 = x/9?

Back

Cross multiply: 2 * 9 = 3 * 6. Since 18 = 18, x = 6 is correct.

Front

What is the value of k in the proportion 5/k = 1/3?

Back

k = 15.

Front

If a recipe calls for 2 cups of flour for every 3 cups of sugar, what is the ratio of flour to sugar?

Back

The ratio of flour to sugar is 2:3.