Setting Up Proportions

Front

What is a proportion?

Back

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

Front

How do you set up a proportion?

Back

To set up a proportion, you can use the formula \( \frac{a}{b} = \frac{c}{d} \), where a and b are part of one ratio, and c and d are part of another.

Front

If 14 sticks of pepperoni are needed for 28 pizzas, how many sticks are needed for 1 pizza?

Back

1 stick of pepperoni is needed for 2 pizzas.

Front

If a car travels 420 miles in 8 hours, what is the rate of travel in miles per hour?

Back

The rate is 52.5 miles per hour.

Front

If Danielle used 8 centimeters of tape for 4 presents, how much tape is used per present?

Back

2 centimeters of tape is used per present.

Front

If Pablo's Macho Tacos sells 7 burritos for every 9 tacos, what is the ratio of burritos to tacos?

Back

The ratio of burritos to tacos is 7:9.

Front

How do you find an unknown in a proportion?

Back

Cross-multiply the known values and solve for the unknown.

Front

What is the cross-multiplication method?

Back

Cross-multiplication involves multiplying the numerator of one ratio by the denominator of the other ratio.

Front

If Ms. King's class has 25 students with 16 boys, what is the ratio of boys to total students?

Back

The ratio is 16:25.

Front

If the class size increases to 40 students, how many boys would there be if the ratio remains the same?

Back

There would be 25.6 boys, which rounds to 26 boys.