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 a/b = c/d, where a and b are the first ratio, and c and d are the second ratio.

Front

If 14 sticks of pepperoni make 28 pizzas, how do you find the number of sticks needed for 36 pizzas?

Back

Set up the proportion: 14/28 = x/36, then solve for x.

Front

What is cross-multiplication in proportions?

Back

Cross-multiplication is a method used to solve proportions by multiplying the numerator of one ratio by the denominator of the other ratio.

Front

If Krystal sold 56 subscriptions in 72 days, how can you find the number of subscriptions sold in 216 days?

Back

Set up the proportion: 56/72 = x/216, then solve for x.

Front

How do you find a missing value in a proportion?

Back

You can find a missing value by cross-multiplying and then solving the resulting equation.

Front

What is the relationship between the number of students surveyed and those who like pizza?

Back

The relationship can be expressed as a ratio, which can be used to set up a proportion.

Front

If 30 out of 50 students like pizza, how do you find out how many out of 190 would like pizza?

Back

Set up the proportion: 30/50 = x/190, then solve for x.

Front

How do you determine the total number of students earning an A in Ms. Ginsberg's class?

Back

Use the ratio of students with an A to the total number of students to set up a proportion.

Front

If 18 out of 30 students have an A, how many out of 80 would have an A?

Back

Set up the proportion: 18/30 = x/80, then solve for x.